Barack Obama’s disapproval rating has been notching upward during the summer and fall, to the point where about 44 percent of Americans polled now have an unfavorable opinion of his performance. Republicans have rejoiced, but there’s bad news for them, too — the GOP’s favorability rating is now a 25-year-low 36 percent, according to CNN/Opinion Research. How would Americans vote if there were a “none of the above” option on their ballots?