Disapproval Rating: 32 Percent
Approval Rating: 43 Percent
No Opinion: 25 Percent
This freshman Republican out of Wisconsin is up for re-election in 2016, and the Washington Post declared he was the "most vulnerable senator on the map." In 2010, Johnson defeated then-Sen. Russ Feingold, a Democrat who had served in the Senate since 1993. This year's race will be a rematch between the two.
