And Salmon himself is firmly against authorizing a strike. “I don’t see any national-security imperative for our country at all. Both sides in this equation are bad actors.” He also notes that Obama has been unable to form an international coalition and hasn’t laid out an overall objective for a missile strike. “Other than saving face for the president, I don’t understand what we would be doing,” he says.

Further, Salmon doubts the intervention will be brief. “Nobody believes this is going to be a couple surgical strikes,” he says.

Salmon agrees the dynamics of the vote are likely to mirror the July vote on an amendment from Representative Justin Amash to reign in the NSA’s broad surveillance powers, except the vote against authorizing Syrian intervention is likely to have more support. The authorization “will fail by 20 votes,” he predicts.