Inside the Arabella Advisors Network: The Dark Money Architecture Behind American Progressive Causes

In November 2025, the Washington, D.C. consulting firm Arabella Advisors announced that its core fiscal-sponsorship business had been acquired by a newly formed entity called Sunflower Services. Arabella itself was renamed Vital Impact. The reorganization affected the largest and most active donor-advisory operation in American progressive politics — a network that, according to combined IRS Form 990 filings analyzed by the Capital Research Center and the Washington Examiner, raised approximately $1.5 billion in 2024 alone.

The Arabella network is unusual in modern American philanthropy in two respects. First, it operates a for-profit consulting hub at the center of a series of nonprofit affiliates rather than the more conventional reverse arrangement. Second, the affiliated nonprofits — known collectively as the “seven sisters” — function as fiscal sponsors for hundreds of smaller organizations that operate without independent legal identity, financial disclosure, or in many cases, public visibility.

The structure has drawn scrutiny from federal regulators, state attorneys general, members of Congress in both parties, and major institutional donors including the Bill and Melinda Gates Foundation, which announced in August 2025 that it had ceased grantmaking to organizations administered through the network.

Background and Origins

Arabella Advisors was founded in 2005 by Eric Kessler, a former appointee in the Clinton administration. The firm’s stated business is providing strategic philanthropic advisory services to high-net-worth donors. Its operational model evolved over the following decade into the management of an interconnected set of 501(c)(3) public charities and 501(c)(4) social welfare organizations, all of which paid Arabella consulting fees while serving as funding intermediaries for progressive causes.

The first nonprofit established under the model — originally called the Arabella Legacy Fund — was renamed the New Venture Fund and remains the largest entity in the network. Three additional 501(c)(3) organizations were subsequently founded: the Hopewell Fund, the Windward Fund, and the Telescope Fund. The 501(c)(4) advocacy arms include the Sixteen Thirty Fund and the North Fund. An additional newer entity, the Impetus Fund, completes the current “seven sisters” structure as documented by InfluenceWatch.

In simple terms: the c(3) organizations handle research and grantmaking. The c(4) organizations handle lobbying and political advocacy. Arabella provided the back-office services that connected them.

How Fiscal Sponsorship Works

Fiscal sponsorship is a legal arrangement in which an established nonprofit provides administrative infrastructure, legal compliance services, tax-exempt status, and human resources support to a smaller project that has not registered as an independent entity with the Internal Revenue Service.

The arrangement is legitimate and widely used in nonprofit administration. Universities, churches, and community foundations routinely act as fiscal sponsors for affiliated programs. The distinguishing feature of the Arabella model is scale and political activity: according to OpenSecrets, the Sixteen Thirty Fund and New Venture Fund have together fiscally sponsored at least 80 of their own affiliated entities.

These affiliated projects often operate under brand names that suggest local, grassroots, or independent origin. The Sixteen Thirty Fund alone operates under dozens of trade names including Arizonans United for Health Care, Floridians for a Fair Shake, Michigan Families for Economic Prosperity, and North Carolinians for a Fair Economy. These entities do not file independent IRS Form 990 disclosures and are not required to publicly identify their funders.

According to the New York Times, the structure makes it possible to observe money entering the network and exiting it, but it does not make it possible to connect any particular donor’s contribution to any particular grant or political expenditure.

Documented Financial Scale

Combined revenues across the four largest Arabella-affiliated nonprofits (the New Venture Fund, the Sixteen Thirty Fund, the Hopewell Fund, and the Windward Fund) totaled approximately $5 billion from 2019 through 2022, according to Capital Research Center analysis of public IRS filings. The full seven-sister network reported combined revenues of approximately $9.2 billion between 2006 and 2023, and combined expenditures of $7.8 billion over the same period.

The Sixteen Thirty Fund alone spent approximately $311 million on progressive causes in 2024 — more than double its 2023 outlay, according to Politico. Its 2020 cycle spending of $410 million made it the largest single 501(c)(4) electoral-cycle spender on the political left in U.S. history to that point.

According to InfluenceWatch and Tablet Magazine, the Arabella-affiliated nonprofits have collectively paid Arabella Advisors more than $230 million in consulting fees over the network’s history.

Foreign Funding and Ballot Measures

A specific element of the Arabella network has drawn cross-partisan concern: the use of 501(c)(4) funds to support state-level ballot measure campaigns. Federal law prohibits foreign nationals from donating to federal candidates, campaigns, or super PACs, but ballot measures are not classified as candidate elections and have historically operated under different state-level rules.

Swiss billionaire Hansjörg Wyss has donated approximately $245 million to the Sixteen Thirty Fund and the New Venture Fund since 2016, according to reporting by The New York Times and Americans for Public Trust. The Sixteen Thirty Fund has spent more than $130 million on state ballot measures across 25 states between 2017 and 2024.

In response to these concerns, several states — including Indiana, Kansas, Kentucky, Arkansas, and Wyoming — have enacted legislation specifically prohibiting foreign-source funding of state ballot measure campaigns. The constitutionality of such restrictions is the subject of ongoing litigation.

In simple terms: the loophole is that money classified as “issue advocacy” can come from sources that direct candidate spending cannot.

Regulatory and Legal Scrutiny

The District of Columbia Attorney General opened an investigation into Arabella Advisors and its affiliated nonprofits in September 2023. The investigation, documented in subpoenas reported by the Washington Examiner, sought records related to potential illegal political spending in and after the 2020 election cycle, as well as potential self-dealing by Arabella in its consulting fee arrangements.

In 2022, the Federal Election Commission concluded that the Sixteen Thirty Fund should be required to register as a political committee, which would impose substantially greater donor disclosure obligations. The matter remains pending as of early 2026.

The November 2025 reorganization into Sunflower Services has raised additional regulatory questions. Right-of-center nonprofit researchers including Capital Research Center President Scott Walter have suggested the reorganization may serve to functionally separate the c(3) and c(4) operations, potentially in response to anticipated IRS scrutiny under the second Trump administration. Sixteen Thirty Fund did not take an ownership stake in Sunflower Services and instead contracts with the new entity for administrative services. The other primary c(4) affiliate, the North Fund, has not announced its disposition.

Comparative Context

It is accurate to note that politically active dark-money networks exist on both sides of the American ideological spectrum. The Koch network of donors, the Leonard Leo-affiliated Marble Freedom Trust, and Donors Trust have collectively channeled comparable sums into conservative causes over similar timeframes. According to the New York Times, the Marble Freedom Trust received a single $1.6 billion contribution from electronics manufacturer Barre Seid in 2021 — at the time the largest known single political contribution in American history.

The Arabella network is distinctive less for its existence than for its scale, its centralized for-profit management structure, and its operational reliance on fiscal sponsorship as a tool for creating apparent grassroots organizations.

Analysis: A Structural Question

Defenders of the Arabella model argue that it represents a legitimate response to comparable conservative donor infrastructure and that its activities operate fully within existing law. They note that the secrecy involved is no greater than that maintained by analogous right-of-center networks, and that the policy outcomes the network has supported — including expanded ballot access, abortion rights, climate policy, and labor protections — reflect majoritarian preferences in many of the states where the spending occurred.

Critics argue that the model represents a fundamental challenge to the disclosure assumptions that underlie American campaign finance law. They contend that fiscal sponsorship of pop-up organizations operates as a legal mechanism to obscure the relationship between donors and political activity, and that the involvement of foreign nationals in U.S. ballot measure campaigns represents a category of influence that existing law was not designed to address.

The Bill and Melinda Gates Foundation’s August 2025 decision to cease grantmaking through Arabella-administered nonprofits was a notable institutional defection. The Gates Foundation had been one of the network’s earliest and largest funders, providing approximately $450 million in support across 16 years.

Conclusion

The Arabella to Sunflower Services transition does not appear to alter the underlying scale or political activity of the affiliated nonprofit network. Combined revenues remain in the multibillion-dollar range. The Sixteen Thirty Fund continues to spend hundreds of millions of dollars on progressive causes. The fiscal sponsorship model continues to incubate dozens of trade-name affiliates across the United States.

What has changed is the level of public, regulatory, and institutional scrutiny. Federal indictments of related nonprofits, congressional inquiries into associated programs, state attorney general investigations, and the withdrawal of major institutional funders all suggest that the operating environment for the network in 2026 differs substantially from the one that prevailed during its expansion period from 2016 through 2022.

Key Takeaways

• The Arabella Advisors network — rebranded as Sunflower Services in November 2025 — manages seven affiliated nonprofits with combined 2024 revenues of approximately $1.5 billion.
• The largest entities include the Sixteen Thirty Fund (501(c)(4)), the New Venture Fund, the Hopewell Fund, and the Windward Fund.
• The network has fiscally sponsored at least 80 affiliated projects operating under trade names that often suggest local or grassroots origin.
• Swiss billionaire Hansjörg Wyss has contributed approximately $245 million to network entities since 2016, raising legal questions about foreign funding of U.S. ballot measure campaigns.
• The District of Columbia Attorney General opened an investigation in September 2023, and the Bill and Melinda Gates Foundation ceased grantmaking through the network in August 2025.

Sources

1. The New York Times, “Arabella Advisors and the Network of Liberal Dark Money,” April 2021 and August 2025.
2. Capital Research Center, “Donors to the Arabella Advisors Network,” December 2024.
3. InfluenceWatch, “Arabella Advisors” organization profile, accessed November 2025.
4. Politico, “Sixteen Thirty Fund saw spending, fundraising dip ahead of 2024,” November 14, 2024.
5. Washington Examiner, “The fall and rise of the Left’s premier dark money network,” January 7, 2026.
6. The Daily Signal, “What, Exactly, Just Happened to the Left’s Dark Money Behemoth Arabella Advisors?” November 23, 2025.
7. Tablet Magazine, “Examining Arabella Advisors Dark Money Lobbying Power,” September 14, 2022.
8. Americans for Public Trust, ballot measure spending analysis, 2024.