Will supporters of the Iran deal be able to filibuster a resolution of disapproval?  

That’s been the question since Sen. Barbara A. Mikulski, D-Md., announced her support Wednesday, bringing the tally to 34 and giving supporters the votes needed to kill a veto override.  

On Thursday, three more senators — Heidi Heitkamp, D-N.D.; Cory Booker, D-N.J.; and Mark Warner, D-Va. — brought the count to 37, four short of the 41 votes needed to filibuster. Unless Democrats succeed in filibustering, Congress would send a resolution of disapproval to the White House, forcing President Barack Obama to have to veto the deal.  

The White House is pushing for as many votes against the resolution as possible, and Obama has a pretty good track record of blocking bills he opposes before they reach his desk. The only exception so far this year is the Keystone XL pipeline approval bill.  

The Democratic senators who have yet to announce are: Michael Bennet of Colorado, Richard Blumenthal of Connecticut, Maria Cantwell of Washington, Benjamin L. Cardin of Maryland, Joe Manchin III of West Virginia, Gary Peters of Michigan and Ron Wyden of Oregon.  

Republican Susan Collins of Maine also hasn’t announced a position.  

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