Franken's job approval rating is up to 55 percent with less than a third of voters disapproving of his work, according to the poll. That's a steady rise from the 41 percent job approval rating he had in the newspaper's first poll after he won a Senate seat during the 2008 election.

Franken's personal approval ratings are a bit lower, however: 42 percent view him favorably, with 31 percent viewing him unfavorably.

Still, those are good numbers for the senator who had the narrowest election win in 2008. Franken appears to be in a strong position heading into his first reelection campaign. The Republicans running against him are businessman Mike McFadden (R) and Minnesota state Rep. Jim Abeler (R).

The poll of 800 Minnesota adults was conducted from June 11-13 and has a margin of error of plus or minus 3.5 percentage points.