Believe it or not, it is far more likely the Democrat Senate passed it knowing full well it will not survive the House, and conference committee report.
Obama will not sign, he has too much skin in the Carbon game. Europe is his "Base", not any American interest in Carbon relief.
Now if Romney wins, and the House stays Republican, the Senate Democrats are screwed; they have a minimum of two years to rehabilitate their reputation prior to the earliest re-election campaign.