While many Senate Democrats said Sen. Rand Paul (R-Ky.) raised legitimate concerns about the Obama administration's drone program during his epic filibuster of John Brennan's nomination as CIA director, most of them were unable to explain why they didn't join him on the Senate floor.

Sen. Ron Wyden (D-Ore.) was the only Democrat to join Paul and 14 other Republicans in a 13-hour filibuster Wednesday. Senate Majority Whip Dick Durbin (D-Ill.) also took to the floor twice, but mostly to defend the U.S. government's authority to target American citizens in "extraordinary circumstances."

"I don't know, there's a lot of debates I don't join that I agree -- I've got stuff to do and was doing a lot of other things," Sen. Sherrod Brown (D-Ohio) told HuffPost when asked about his whereabouts the day before. "I think the question should be answered. I think [Sen.] Paul was generally right on it."