President Obama, along with other members of the international community, is moving toward closing a historic deal with Iran, which would involve laying out restrictions on that country's nuclear program in exchange for a withdrawal of sanctions. The deal, which is due to be concluded in June, has been hailed as an important step toward avoiding war across the world.

However, there is one group of hardliners who continue to do everything they can to scuttle a diplomatic solution. They're in the U.S. Congress, not in Tehran, and most of the would-be saboteurs are Republicans, with Arkansas's Senator Tom Cotton leading the charge. But a significant number of Senate Democrats have signed onto legislation sponsored by both Cotton and bill author Sen. Bob Corker (R-TN) that would attempt to force the administration to bring the deal to Congress to be approved.

The Democratic sponsors of the Corker legislation all have one thing in common: support from the pro-Israel lobby.

1. Senator Bob Menendez (D-NJ), pro-Israel cash: $341, 170.

Menendez, who has been indicted following allegations he did special favors for a Florida-based donor, is one of the prime movers of the Corker legislation. Of any Democrat in the Senate, he is the favorite of pro-Israel donors.

2. Senator Tim Kaine (D-VA), pro-Israel cash: $256,020.

Kaine is one of the original cosponsors of the Corker bill, and boasts that there is “zero chance” the bill would harm negotiations; yet he fails to explain how a GOP Congress that subverted President Obama to invite the Israeli Prime Minister could possibly vote to approve an Iran deal.

3. Senator Chuck Schumer (D-NY), pro-Israel cash: $258,999.

Schumer, slated to become the Democrats' Senate leader after the retirement of Sen. Harry Reid (D-NV), was a late sponsor of the legislation. His support for the bill has earned the ire of progressive advocacy groups that say he cannot lead the Democrats while helping scuttle diplomacy.

4. Senator Bill Nelson (D-FL), pro-Israel cash: $262,500.

Nelson has rebuked a similar effort by Senate Majority Leader Mitch McConnell (R-KY) to force a vote on the Iran deal, yet he was an original co-sponsor of the Corker bill.

5. Senator Joe Donnelly (D-IN), pro-Israel cash: $79,062.

Donnelly told the local news he's taking “a look at all of the terms of the agreement right now,” but was an original co-sponsor of the Corker legislation.

6. Senator Heidi Heitkamp (D-ND), pro-Israel cash: $79,062.

Despite rebuking the letter from Sen.Tom Cotton (R-AR) for his letter to Iran, Heitkamp is a strong supporter of the Corker bill.

7. Senator Michael Bennet (D-CO), pro-Israel cash: $109,126.

Bennet was not an original cosponsor of the bill, but signed on early last month.

8. Senator Richard Blumenthal (D-CT), pro-Israel cash: $80, 640.

When the final framework was reached in early April, Blumenthal put out a statement insisting that Congress has a “role in scrutinizing this framework and any final agreement.”

This week the Corker bill saw unexpected changes, however, which weakened Congress' path to kill a deal. Under the new language, both houses of Congress would have to sustain a veto-proof majority to disapprove of the deal in order to kill it, meaning that there only need to be 34 senators in favor of the deal to sustain it. This provides a lifeline that could allow negotiators the room they need to strike a deal, even one that the Israel lobby's friends in Congress cannot block.