Sen. Al Franken (D-Minn.), who won his seat by the smallest of margins in 2008, is looking like a pretty strong favorite in 2014.

A new poll from the Minneapolis Star-Tribune shows Franken's approval rating rising to 55 percent -- extremely positive territory for a member of Congress these days -- while fewer than one-third of respondents disapprove of him.

Franken remains somewhat undefined, though, and even many who approve of his job performance aren't sure what they think of him personally.

Overall, 31 percent of Minnesotans aren't sure how they feel about Franken personally, while 41 percent view him favorably and 25 percent view him unfavorably.

The GOP has not made Franken a top target in 2014, and some top potential challengers have passed on the race. Currently, the GOP field features businessman Mike McFadden and state Rep. Jim Abeler.