A Republican super PAC is funding an outside effort to help reelect Democratic Rep. Eliot Engel, locked in a tight primary against insurgent Jamaal Bowman.

The super PAC is called Americans for Tomorrow’s Future, following in the proud tradition of nonsensically named political action committees. The connections to the GOP are apparent enough that the Center for Responsive Politics lists it as “Republican/Conservative.” The PAC’s treasurer, David Satterfield, is a former aide to one-time Republican Senate Leader Bill Frist. Satterfield works now at Huckaby Davis Lisker, a prominent firm that does election compliance and accounting work for Republican campaigns. This cycle, the firm is handling the accounts for the National Republican Senatorial Committee, National Republican Congressional Committee, and the campaign of Senate Majority Leader Mitch McConnell, among dozens of other GOP operations.

The PAC, presumably due to its visible Republican ties, is not spending directly in Engel’s New York primary. Instead, it funneled $100,000 to another super PAC, called Democratic Majority for Israel, on May 27. DMFI, a controversial operation inside the Democratic coalition, spent heavily against Sen. Bernie Sanders in the Democratic presidential primary, with help from the American Israel Public Affairs Committee, AIPAC, The Intercept reported in February.

Since cashing the Americans for Tomorrow’s Future check, DMFI has spent more than $600,000 boosting Engel and hitting Bowman on TV, and with digital ads, mailers, and paid phone banking. DMFI has not spent money on any other race since taking money from the GOP operation.

The congressman, who’s been in office for over three decades, is the chair of the House Foreign Relations Committee, where he has served since 1994. From that perch, he has been particularly conservative on policy toward Israel, even as the base of the Democratic Party moves leftward on the U.S.-Israel alliance. Pro-Israel groups have contributed more than $1.3 million to Engel over the course of his career. NORPAC, another pro-Israel PAC, is Engel’s second largest contributor this cycle, after the Pro-Israel America PAC, and has given his campaigns $132,509 throughout his career. While Bowman’s campaign is focused on issues like health care, housing, education, and justice reform more than foreign policy, he would certainly be more progressive than Engel, whose loss would be a major blow to leading pro-Israel political groups.

NORPAC is now sounding the alarm about Engel’s race.

The donors to Americans for Tomorrow’s Future all give heavily to Republican causes, and some give to Democrats as well. Herbert Shear of Palm Beach, Florida, for instance, a longtime CEO of a logistics firm, has given $100,000 to the PAC, and has also maxed out to President Donald Trump, giving $35,000 to the Republican National Committee and $50,000 to the Trump Victory Committee. Other major donors to ATF have similar giving histories; the PAC has raised just over $600,000 from a handful of donors this cycle.

Recent donors to DMFI include Qualcomm co-founder Andrew Viterbi, who has given $195,000 this year, including a single contribution of $100,000 in March; Linda C. Dresner, a philanthropist in Birmingham, Michigan, who listed her occupation as homemaker and donates frequently to Democrats and Republicans, including Senate Majority Leader Mitch McConnell and Democratic Rep. Daniel Lipinski, contributed $100,000 in February; and real estate executive Mark Rubin, president of Maric Inc., a Boston firm, who gave $45,000 to DMFI in March and has given to Republicans and Democrats since the 1990s (including Lipinski, Democratic Rep. Henry Cuellar, Texas Republican Sen. Ted Cruz, and former New Hampshire Republican Sen. Kelly Ayotte).

Engel is on the receiving end of nearly $1 million of outside big money and counting, including funding from two other dark-money groups that can’t be traced. One group is called Avacy Initiatives Inc., and has reported spending roughly $120,000 so far to boost Engel, using the firm Red Mountain Media LLC, which has left precious little digital footprint.

The only other spending that dark-money group has done was in support of Teresa Leger Fernandez, who recently won a New Mexico congressional primary against Valerie Plame, who came under fire for a series of anti-Semitic Twitter posts.

Another dark-money group, Perise Practical Inc., has spent $180,000 in support of Engel. It also spent on behalf of Leger Fernandez, and also uses Red Mountain Media LLC for its spending. Both groups have the same treasurer on their founding documents, David Krone, the former chief of staff to former Democratic Senate Majority Leader Harry Reid.

While Krone’s affiliation implies that the money has roots in Democratic circles, the byzantine structure of the spending raises questions about the actual source of the money. If Democrats want to spend money supporting a Democrat who is strongly supportive of Israel in a primary, they have plenty of ways to do so — DMFI among them — and are not typically shy about doing so publicly. But Republican spending in a primary can backfire, as Democratic primary voters reject the intervention by the opposing party. Earlier this year, the revelation that Koch Industries money was backing Cuellar in his primary became a political handicap, and Cuellar attempted to deny it happened. Cuellar defeated his primary opponent, insurgent Jessica Cisneros, by 2,700 votes.

Reid, while Senate majority leader, kept warm relations with some major GOP donors, whose interest in supporting gambling legislation — such as billionaire Sheldon Adelson — coincided with Reid’s interest in supporting the business that fuels Las Vegas. Adelson, who is generally toxic in Democratic circles, is one of the country’s most financially generous backers of pro-Israel politicians.

In late January, The Intercept reported, DMFI PAC ran $800,000 worth of negative ads in Iowa against Sanders ahead of the February 3 caucus. AIPAC helped fund those ads, allowing contributions from members to DMFI to count toward their AIPAC tier and related benefits. AIPAC denied the arrangement, and a DMFI spokesperson said they had no knowledge of it.

A spokesperson for Engel’s campaign said they had no connection to Americans for Tomorrow’s Future, Perise Practical, or Avacy. (Federal law bars political campaigns from coordinating with dark-money groups.)

“Congressman Engel is endorsed by End Citizens United and authored a Constitutional Amendment to ban PACs, codify the Voting Rights Act, and abolish the electoral college,” a spokesperson said in a statement. “He’s on the record as preferring a New York City style public financing system with matching funds.” In her first House Democratic primary endorsement this cycle, Hillary Clinton backed Engel on Monday. The Congressional Black Caucus PAC endorsed Engel in May.

Bowman has backing from Justice Democrats, which recently launched a super PAC, and has spent $500,000 supporting him on air. The PAC doesn’t have to disclose its donors until well after the primary. Bowman is not accepting corporate PAC or lobbyist money, and his campaign raised more $750,000 than this month, with more than 25,000 donations.

Bowman recently won endorsements from neighboring Rep. Alexandria Ocasio-Cortez, Sanders, the New York Times editorial board, and California Democratic Rep. Katie Porter. Andom Ghebreghiorgis, a fellow local educator who dropped out of the race earlier this month, also gave his backing to Bowman. The Democratic Socialists of America endorsed Bowman Monday.

Engel’s long, hawkish record and ties to the defense industry has been a liability, particularly given the strength of his competition, but have also drawn big-money backers. Engel admitted last month that he had not stepped foot in his district throughout the coronavirus pandemic. Under pressure, he returned to the district, and just two weeks ago, with hot mics running, Bronx Borough President Ruben Diaz Jr. ran through a list of officials slated to speak at the press conference, a list that did not include Engel.

Engel pleaded for a spot, telling Diaz, twice, “If I didn’t have a primary, I wouldn’t care.”