While Stabenow's job approval numbers had held steady, Hoekstra's had dipped 20 points amongst independents.

He still holds a strong lead over his primary foes, with 42 percent support to 9 percent for Clark Durant. But that's down from 78 percent support in the July poll.

The poll was conducted from Feb. 10-12 and has a margin of error of plus or minus 4.1 percent for the general election and 4.9 percent for the primary.