The Huffington Post is reporting that Chuck Schumer will come out against the Iran Nuke Deal:

New York Sen. Chuck Schumer, the chamber’s third-ranking Democrat, plans to announce his opposition to the nuclear deal negotiated by the U.S., Iran, and five world powers tomorrow, three people familiar with his thinking tell The Huffington Post.

Schumer’s move will come a day after New Hampshire Democratic Sen. Jeanne Shaheen and Schumer’s fellow New York senator, Kirstin Gillibrand, announced their support for the deal. That momentum is blunted by Schumer’s pending announcement. Backers of the deal had hoped that if Schumer decided to oppose the deal, he would hold off until the last minute.

(added) Schumer made the announcement Thursday night, as reported by CNN:

New York Sen. Chuck Schumer, an influential Jewish Democrat who’s poised to assume leadership of his party in the Senate, will oppose President Barack Obama’s nuclear deal with Iran, he announced on Thursday evening.

“After deep study, careful thought and considerable soul-searching, I have decided I must oppose the agreement and will vote yes on a motion of disapproval,” Schumer wrote in a 1,600-word post on the website Medium that posted during the first Republican presidential debate.

“I will vote to disapprove the agreement, not because I believe war is a viable or desirable option, nor to challenge the path of diplomacy,” he added later. “It is because I believe Iran will not change, and under this agreement it will be able to achieve its dual goals of eliminating sanctions while ultimately retaining its nuclear and non-nuclear power.”

Will this break the deal? Remember, Democrats only need 1/3 of the Chamber to block opposition to the deal. So unless he lobbies his colleagues really hard, this may be just a courtesy vote.

UPDATE 8-7-2015: It certainly is interesting that Schumer, who is relentless to get in front of cameras, made his announcement Thursday night when all media attention was focused on the Republican debate. That certainly suggests that his vote is CYA. And this CNN report also suggests the same:

He’s the most influential Democrat to come out in opposition to the deal, a stance long sought by the agreement’s opponents, many of whom are his constituents.

But the decision to make his position public on the heels of a string of endorsements was being seen in the White House as a signal that it has a veto-proof number of supporters and it was safe for Schumer to oppose the deal without jeopardizing the President’s agenda.

“We’re very confident that we can hold that veto, with the Democratic Caucus in the House and also the Senate,” Ben Rhodes, the President’s deputy national security advisor, told CNN on Wednesday.

That feeling in bolstered by Schumer’s own statement that he’s not going to lobby his colleagues very hard, via The Hill:

“There are some who believe that I can force my colleagues to vote my way,” Schumer said a separate statement Thursday evening. “While I will certainly share my view and try to persuade them that the vote to disapprove is the right one, in my experience with matters of conscience and great consequence like this, each member ultimately comes to their own conclusion.”

Schumer has an Op-Ed in The NY Post today, Why I’m opposing the Iran nuclear deal, which is listed as an “excerpt” of his announcement Thursday night:

Therefore, I’ll vote to disapprove the agreement, not because I believe war is a viable or desirable option, nor to challenge the path of diplomacy. It is because I believe Iran won’t change, and under this agreement it will be able to achieve its dual goals of eliminating sanctions while ultimately retaining its nuclear and non-nuclear power.

Better to keep US sanctions in place, strengthen them, enforce secondary sanctions on other nations and pursue the hard-trodden path of diplomacy once more, difficult as it may be.

(added) Hmmm — Did White House force the leak Thursday night to make sure Schumer didn’t get attention? Jonah Goldberg wonders if that was an Obama miscalculation: