Company lists · Data refreshed September 2026

Top 25 Grassroots advocacy firms based in the United States

Name: Grassroots advocacy firms based in the United States
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 20, 2026 2,026 companies tracked

RevenueBase identified 2,026 grassroots advocacy firms headquartered in the United States as of September 2026 and tracks 20,123 professional contacts across them, including 8,822 with verified work emails. Washington is the largest hub.

This list covers grassroots advocacy firms headquartered in the United States, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 20, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 20, 2026 86% judged on-target in blind review

2,026Companies

20,123Contacts tracked

8,822Verified emails

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The 25 largest grassroots advocacy firms based in the United States

Ranked by team size

Top 25 of 2,026 grassroots advocacy firms based in the United States, ranked by team size, largest first. Data refreshed Sep 20, 2026. RevenueBase Smart Search rates how each company's information relates to grassroots advocacy firms: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#	Company	RevenueBase Smart Search	Headquarters	Employees	Contacts
1	DDC Public Affairs	Partial evidence	Washington, DC, United StatesHQ checked Sep 20, 2026	51-200	411 contacts →
	Partial evidence “DDC Public Affairs builds communities of advocates that impact policy and win campaigns.” Source: RevenueBase Database · checked Sep 20, 2026
2	The Outreach Team	Indirect evidence	Ithaca, NY, United StatesHQ checked Sep 20, 2026	201-500	398 contacts →
	Indirect evidence “The Outreach Team is a national consulting firm working to make the world a better place.” Source: RevenueBase Database · checked Sep 20, 2026
3	Mercury Public Affairs, LLC	Indirect evidence	New York, NY, United StatesHQ checked Sep 20, 2026	51-200	390 contacts →
	Indirect evidence “Mercury is a national bipartisan government relations and strategic communications firm.” Source: RevenueBase Database · checked Sep 20, 2026
4	Quorum	Indirect evidence	Washington, DC, United StatesHQ checked Sep 20, 2026	201-500	357 contacts →
	Indirect evidence “Quorum is your AI-powered public affairs software to get information and execute strategy all in one place.” Source: RevenueBase Database · checked Sep 20, 2026
5	Fieldworks	Partial evidence	Washington, DC, United StatesHQ checked Sep 20, 2026	5,001-10,000	336 contacts →
	Partial evidence “FieldWorks brings innovative grassroots and field strategies to Democratic and progressive campaigns and organizations.” Source: RevenueBase Database · checked Sep 20, 2026
6	Cornerstone Government Affairs	Indirect evidence	Washington, DC, United StatesHQ checked Sep 20, 2026	201-500	255 contacts →
	Indirect evidence “Cornerstone Government Affairs is a full-service, bipartisan, employee-owned firm specializing in government relations and lobbying, public affairs, strategic communications, and…” Source: RevenueBase Database · checked Sep 20, 2026
7	BGR Group	Partial evidence	Washington, DC, United StatesHQ checked Sep 20, 2026	51-200	243 contacts →
	Partial evidence “The Services You Need BGR Group offers an integrated suite of bipartisan lobbying, strategic communications and advocacy solutions that help meet challenges in a risky…” Source: RevenueBase Database · checked Sep 20, 2026
8	GMMB	Indirect evidence	Washington, DC, United StatesHQ checked Sep 20, 2026	201-500	239 contacts →
	Indirect evidence “We’re bold.” Source: RevenueBase Database · checked Sep 20, 2026
9	Cohen Milstein Sellers & Toll LLP	Indirect evidence	Washington, DC, United StatesHQ checked Sep 20, 2026	51-200	236 contacts →
	Indirect evidence “Cohen Milstein Sellers & Toll LLP champions the causes of real people-workers, consumers, small business owners, investors, and whistleblowers-working to deliver corporate reforms…” Source: RevenueBase Database · checked Sep 20, 2026
10	Missionwired	Indirect evidence	Washington, DC, United StatesHQ checked Sep 20, 2026	201-500	226 contacts →
	Indirect evidence “At MissionWired, we believe your world-changing cause deserves more than marginal gains.” Source: RevenueBase Database · checked Sep 20, 2026
11	AVŌQ	Indirect evidence	Washington, DC, United StatesHQ checked Sep 20, 2026	201-500	205 contacts →
	Indirect evidence “Excellence isn’t enough.” Source: RevenueBase Database · checked Sep 20, 2026
12	DCI	Strong evidence	Washington, DC, United StatesHQ checked Sep 20, 2026	51-200	198 contacts →
	Strong evidence “DCI Group is an independent public affairs consulting firm that specializes in public relations, crisis management, grassroots engagement, and digital advocacy.” Source: RevenueBase Database · checked Sep 20, 2026
13	Public Citizen	Partial evidence	Washington, DC, United StatesHQ checked Sep 20, 2026	51-200	195 contacts →
	Partial evidence “Public Citizen is a nonprofit consumer advocacy organization that champions the public interest – your interests – in the halls of power.” Source: RevenueBase Database · checked Sep 20, 2026
14	Plus Communications	Indirect evidence	Arlington, VA, United StatesHQ checked Sep 20, 2026	201-500	188 contacts →
	Indirect evidence “Strategy + Execution = Results.” Source: RevenueBase Database · checked Sep 20, 2026
15	Lilly & Company	Partial evidence	Austin, TX, United StatesHQ checked Sep 20, 2026	n/a	187 contacts →
	Partial evidence “Since its inception, Lilly & Company has built a unique and comprehensive strategy for providing the best possible services available in political fundraising and grassroots…” Source: RevenueBase Database · checked Sep 20, 2026
16	Global Strategy Group	Indirect evidence	New York, NY, United StatesHQ checked Sep 20, 2026	51-200	179 contacts →
	Indirect evidence “Global Strategy Group is the go-to public affairs, communications, and research partner for companies, causes, and campaigns.” Source: RevenueBase Database · checked Sep 20, 2026
17	Blue State	Indirect evidence	Brooklyn, United StatesHQ checked Sep 20, 2026	201-500	170 contacts →
	Indirect evidence “We believe there’s no force more powerful than people taking collective action on the things they care about.” Source: RevenueBase Database · checked Sep 20, 2026
18	Invariant	Indirect evidence	Washington, DC, United StatesHQ checked Sep 20, 2026	51-200	166 contacts →
	Indirect evidence “Invariant is a bipartisan business advisory firm, providing strategic advice to companies, trade associations, non-profits, and individuals on how to make Washington work for them.” Source: RevenueBase Database · checked Sep 20, 2026
19	Sanford Heisler Sharp Mcknight, LLP	Indirect evidence	New York, NY, United StatesHQ checked Sep 20, 2026	51-200	145 contacts →
	Indirect evidence “At Sanford Heisler Sharp McKnight, our team of knowledgeable attorneys is committed to representing clients in their claims against powerful entities.” Source: RevenueBase Database · checked Sep 20, 2026
20	For OUR Future	Indirect evidence	Washington, DC, United StatesHQ checked Sep 20, 2026	51-200	144 contacts →
	Indirect evidence “For Our Future is a 501(c)(3), 501(c)(4), and PAC that empowers people in battleground states and districts to organize their communities, build progressive power, and fight for a…” Source: RevenueBase Database · checked Sep 20, 2026
21	Purpose	Indirect evidence	New York, NY, United StatesHQ checked Sep 20, 2026	51-200	143 contacts →
	Indirect evidence “We're a strategy consultancy, a creative agency and a social movement incubator.” Source: RevenueBase Database · checked Sep 20, 2026
22	Fenton	Indirect evidence	New York, NY, United StatesHQ checked Sep 20, 2026	51-200	140 contacts →
	Indirect evidence “At Fenton, we are communications strategists for social change.” Source: RevenueBase Database · checked Sep 20, 2026
23	ARGUS	Indirect evidence	Boston, MA, United StatesHQ checked Sep 20, 2026	11-50	133 contacts →
	Indirect evidence Source: RevenueBase Database · checked Sep 20, 2026
24	Mcguirewoods Consulting	Indirect evidence	Richmond, VA, United StatesHQ checked Sep 20, 2026	51-200	127 contacts →
	Indirect evidence “What people say and do in government can have a profound impact on your organization.” Source: RevenueBase Database · checked Sep 20, 2026
25	Indivisible Project	Indirect evidence	Washington, DC, United StatesHQ checked Sep 20, 2026	51-200	123 contacts →
	Indirect evidence “Our mission is to resist Trump’s agenda by empowering local activist groups to make their Members of Congress listen.” Source: RevenueBase Database · checked Sep 20, 2026

RevenueBase Smart Search

RevenueBase Smart Search assesses information from a company’s LinkedIn profile, information supplied directly by the company, its website, and other publicly available sources. It uses that information to rate how closely the company relates to this list’s category: grassroots advocacy firms. Every row carries its rating and the description the rating was read from, so each one can be checked rather than taken on trust.

Strong evidence: The company's own public description of its business names grassroots advocacy firms.
Partial evidence: Its own public description names part of grassroots advocacy firms, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name grassroots advocacy firms. The match rests on the rest of the company's public profile rather than the one sentence quoted here, so this is the rating to check first.

RevenueBase Smart Search is how these lists are built: RevenueBase's data engine and AI assemble the companies that match a category defined in a user's own words, so a list can be about what companies actually do rather than about whichever industry code they were filed under.

Showing 25 of 2,026 grassroots advocacy firms based in the United States

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Grassroots advocacy firms based in the United States at a glance

As of Sep 20, 2026

43.8%Verified-email coverage

9.9Average contacts per company

1-10Median size (employees)

20.5%Largest-city concentration · Washington

Sep 20, 2026Page data refreshed

Companies by employee count

1-10

1,546

11-50

371

51-200

201-500

501-1,000

1,001-5,000

5,001-10,000

10001+

Email recency for this list is measured worldwide rather than for United States, so it is reported there. Company counts and contact totals on this page are exact for United States, over 2,026 companies.

How this list was built

Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among grassroots advocacy firms, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.

Source: The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
What qualifies: Companies headquartered in the United States whose own description of what they do matches “grassroots advocacy firms”. Matching reads each company's description, not its industry code or its name.
RevenueBase Smart Search: RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names grassroots advocacy firms), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
What we exclude: Companies whose own description does not clearly place them among grassroots advocacy firms, and records with no verified work email. Companies headquartered outside United States are excluded even when they keep an office there.
Match quality: In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
Ranking: Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
Verification: Every listed company carries at least one verified work email, 8,822 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
Refresh: This page's figures were pulled from the company graph on September 20, 2026. Lists refresh periodically as the graph is re-checked.
Corrections: Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.

Grassroots advocacy firms by metro

Frequently asked

What is RevenueBase Smart Search?

RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names grassroots advocacy firms, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.

How many grassroots advocacy firms are there based in the United States?

RevenueBase identified 2,026 grassroots advocacy firms headquartered in the United States as of September 2026, matched on each company's own description of what it does rather than its industry code.

What is the largest company on this list?

DDC Public Affairs, headquartered in Washington, tops this list with the largest team on record.

Which city has the most grassroots advocacy firms?

Washington leads with 416 headquartered companies, followed by Sacramento (73) and New York (64).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 8,822 verified decision-maker contacts tracked across these 2,026 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 20, 2026.

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About this data

RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase Smart Search, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.