President Obama got a strong show of support from Jewish members of Congress and Democratic leaders this week in his efforts to negotiate a nuclear deal with Iran.

A letter signed by 150 House Democrats urged the President to "stay on course" for a negotiated "strong and verifiable agreement" that will "prevent Iran from having a nuclear weapon."  They cautioned, "War itself will not make us safe. "

The letter, the initiative of Reps. Jan Schakowsky of Illinois, Lloyd Doggett of Texas and David Price of North Carolina, is a sign of support for Obama if he vetoes a Congressional resolution of disapproval blocking any Iran deal he submits to Congress.

Republicans are determined to block any deal at all costs based on two principles, one specious and the other well founded.

On the first, they are determined to block anything Obama negotiates, regardless of content or quality, just to deny him a foreign policy success and a legacy issue. 

The second is a valid distrust of the Iranian regime.  Ronald Reagan used to say that in any deal with the Soviet Union our approach should be "trust but verify."  Obama has dropped the trust part and emphasized the verify demand.  But can he deliver enough verification to satisfy the Congress? 

Lawmakers will get a chance to decide when they see the actual agreement — if there is one — this summer.  Meanwhile they are reacting to the framework published in April with its contradictory interpretations by the various parties plus the propaganda of the Iranians, who are declaring no inspection of their military facilities and demanding an immediate lifting of all sanctions. Both are unrealistic and only serve to undermine possible future support.

The Senate last week voted 98-1 to approve a bill that will provide for Congressional review of any Iranian agreement and an opportunity to block it.  If the bill survives the House in tact the President said he will sign it.

It gives the Congress up to 52 days to review and vote on the agreement, during which time the President cannot remove any sanctions; if both chambers vote out a resolution of disapproval he can veto it and opponents will need a 2/3 vote in each body to override.

"The problem is that if Congress gets to the point of taking a vote of disapproval, that could cause Iran and the world to question America’s commitment to a final agreement, a potentially disastrous outcome if the deal is sound and verifiable," writes Carol Giacomo in the New York Times.

The Schakowsky letter is a strong indicator that Obama will have the votes to sustain a veto, but it will come down to the contents of the agreement itself and what the Iranians do to convince Americans that it is worth the risks and is verifiable.

Americans for Peace Now noted that "while in no way committing its signers to any specific position with respect to a final deal, [the letter] nonetheless signals that there may well be sufficient support for a deal in Congress to prevent any such veto override."

Seven of the 18 Jewish Democrats in the House signed the letter: Schakowsky, David Cicilline of Rhode Island, Susan Davis of California, Stephen Cohen of Tennessee, Alan Lowenthal of Californian, Jared Polis of Colorado and John Yarmuth of Kentucky.

The House Democratic leader Nancy Pelosi of California and the third ranking leader, Assistant Democratic Leader Jim Clyburn of South Carolina, signed the letter but not her number two, minority whip Steny Hoyer of Maryland.