Updated 12:14 a.m. | Did Sen. Charles E. Schumer just open himself up to a serious challenge to lead Senate Democrats in 2017? Top allies of the president say yes — and a major liberal advocacy group now wants him gone.  

MoveOn.org announced a “donor strike” after the New York Democrat’s announcement that he opposes the Iran deal and compared him to Joseph I. Lieberman, while former senior White House aide Dan Pfeiffer warned the Democratic base wouldn’t support Schumer for leader. What You Missed: Senate Hearing on Iran Nuclear Deal

MoveOn said its 8 million members will withhold funding for the Democratic Senatorial Campaign Committee and from any Democratic candidate who sides with Schumer.  

“While not unexpected, it is outrageous and unacceptable that the Democrat who wants to be the party’s leader in the Senate is siding with the Republican partisans and neoconservative ideologues who are trying to scrap this agreement and put us on the path to war,” said MoveOn.org Political Action Executive Director Ilya Sheyman in a statement.  

“Our country doesn’t need another Joe Lieberman in the Senate, and it certainly doesn’t need him as Democratic leader. The vast majority of Democratic voters — the people who elected President Obama in part because of our shared belief that war must always be a last resort — will not stand for it.”  

And Pfeiffer’s tweets were brutal.  

https://twitter.com/danpfeiffer/status/629478257948295170  

https://twitter.com/danpfeiffer/status/629483147328139264  

Pfeiffer wasn’t the only Obama alum nuking Schumer.  

Jon Favreau, Obama’s former speechwriter, also questioned his viability as leader.  

Chuck Schumer, who said it was a mistake to pass Obamacare, now comes out again the Iran Deal. This is our next Senate leader?

— Jon Favreau (@jonfavs) August 7, 2015

And former Obama national security spokesman Tommy Vietor:

https://twitter.com/TVietor08/status/629477397897723905  

And former Obama campaign spokesman Ben LaBolt.  

https://twitter.com/BenLaBolt/status/629476660434313216  

Republicans, meanwhile, were ebullient, with Don Stewart, a spokesman for Majority Leader Mitch McConnell, happily tweeting out quotes from Schumer’s opposition statement.  

https://twitter.com/StewSays/status/629503753260019712  

While Democratic activists and White House allies might prefer another leader, it’s not clear who would launch such a challenge. Schumer has been the heir apparent after his former roommate, Minority Whip Richard J. Durbin, D-Ill., said he would support him. (Schumer hasn’t returned the favor and endorsed keeping Durbin as his No. 2, however.)  

On the Iran deal, Durbin has been the White House’s most important ally, coming out early for the deal, and had tweets praising him from Favreau and David Axelrod, among others, Thursday night as a result.  

But Schumer has strong relationships across the Democratic members of the Senate and his fundraising ability is unmatched.