by Eli Clifton

Sen. Cory Booker (D-NJ) is feeling the heat. Progressive advocacy groups are pushing Democrats from one side to back the Obama administration’s plan to constrain Iran’s nuclear program. From the other side, meanwhile, New Jersey’s Republican Governor Chris Christie vows to lobby Booker to join the senior senator from New Jersey, Robert Menendez, in opposing the Iran deal.

NJ.com reports that Booker is probably under pressure from NORPAC, the pro-Israel PAC aligned with the American Israel Public Affairs Committee (AIPAC), which has been “Booker’s biggest lifetime source of campaign cash, contributing or raising $158,871.” But NORPAC is only the tip of the iceberg when it comes to Booker’s support. Super PACs underwrote over a million dollars in independent expenditures to support Booker’s 2014 Senate campaign. Two of the most generous of these PACs received funding from Republican millionaires and billionaires opposed to the Iran deal, most of whom don’t even live in Booker’s home state of New Jersey.

According to the non-partisan Center for Responsive Politics, Booker received $732,534 in supportive expenditures from the Independence USA PAC in the 2014 election cycle. Independence USA is exclusively funded by Michael Bloomberg. Writing in an August 10 column for Bloomberg View, the former New York City mayor claimed to be undecided about the Iran deal. But his scolding of the White House’s defense of the deal as “only hurting their credibility” and praise for New York Senator Chuck Schumer’s “thoughtful statement opposing the deal” leave little question about which way Bloomberg is leaning.

Independence USA PAC leaned Republican in 2014, spending $2,078,996 to support Democrats, $2,098,920 to support Republicans, and $1,403,868 against Democrats.

Booker’s second largest outside spender, Mobilization Project, supported only one campaign in the 2014 election cycle: $532,445 for Booker. Mobilization Project received its biggest infusion of cash, $137,564 from hedge funder Edward Nicoll. Hedge fund billionaire Seth Klarman (who serves on the board of the anti-Iran deal group The Israel Project), Michael Fux (who sat on the board of Friends of the Israel Defense Forces) contributed $100,000, and Ravenel B. Curry III (who serves as a trustee of the hawkish American Enterprise Institute) contributed $50,000.

According to the nonpartisan Sunlight Foundation, Klarman directs the vast majority of his political giving to Republicans.

In the 2014 election cycle, Nicoll only supported Booker and Fux directed most of his giving to Booker-supporting groups. Curry’s other major 2014 contribution, $500,000, went to the Freedom Partners Action Fund, which is spearheaded by the Koch brothers.

Michael Bloomberg, Seth Klarman, Edward Nicoll, and Ravenel Curry made their contributions from non-New Jersey addresses, suggesting that only Michael Fux is an actual resident of the state represented by Booker. (Edward Nicoll made campaign contributions from a New Jersey address until 2005.)

Several close friends of Cory Booker—Rabbi Shmuley Boteach, a former Republican congressional candidate, and New Jersey Governor, and Republican presidential candidate, Chris Christie—are pushing him to oppose the Iran deal. Boteach, both through his foundation and his congressional campaign, has been a recipient of GOP megadonor and Iran hawk Sheldon Adelson’s largesse. And Chris Christie’s relationship with Adelson has been an ongoing point of interest for those following the 2016 political horse race.

Booker may balk at the pressure and back Obama’s signature foreign policy accomplishment. But it will require standing up to a group of powerful and deep pocketed political donors, many of whom don’t reside in New Jersey or regularly support Democrats. Booker’s decision may come down to how big a debt of gratitude he feels he owes to his biggest financial supporters.

Photo of Cory Booker by Jamelle Bouie via Flickr