First, Chairman of the Senate Committee on Banking, Housing, and Urban Affairs Tim JohnsonTim JohnsonCourt ruling could be game changer for Dems in Nevada Bank lobbyists counting down to Shelby’s exit Former GOP senator endorses Clinton after Orlando shooting MORE (D-S.D.) is expected to make a motion to override the rules. Sixty votes will be required just to bring that motion to the floor.

If that cloture vote passes, the Senate will then move to the actual motion to override the rules, which will reacquire just 51 votes.

The Military Construction bill, which included VA funding, is in itself relatively noncontroversial, and Sessions has gone to pains to point out that it is not the bill's content he objects to, calling it a "piece of legislation that will be positive for our country."

H.R. 2055, the Military Construction, Veterans Affairs and Related Agencies appropriations bill, increases funding for the VA by 5.8 percent and cuts military construction spending by $2.6 billion to reflect anticipated base closures and realignments.