Democratic U.S. Sen. Al Franken, widely seen as a top Republican target in 2014, starts the next political cycle with no clear opponent and a 6- to 14-point lead over four potential challengers, according to a Public Policy Polling survey.

The poll finds Franken with a 52 percent approval rating among Minnesota voters, with 41 percent registering disapproval. (The numbers generally break down along party lines, with 89 percent of Democrats approving, 83 percent of Republicans disapproving.)

More significant to Franken's fortunes may be what pollsters called a "weak Republican bench" in Minnesota.

In a study of hypothetical matchups, Franken leads former Sen. Norm Coleman (who has said he isn't running) by 6 points (50 to 44), Rep. John Kline by 8 points (49 to 41), Rep. Erik Paulsen by 11 points (50 to 39) and Rep. Michele Bachmann by 14 (54 to 40).

Even more significant, Bachmann, who fared the worst of anyone the pollsters tested against Franken, appears to be the top choice of GOP voters in Minnesota to take him on next year. Among Republicans, 45 percent say they would like her to be their candidate. That compares with 19 percent for Kline, 11 percent for Paulsen, 4 percent for University of Minnesota Regent and former state Rep. Laura Brod and 2 percent for Hennepin County Sheriff Rich Stanek.

(Recently defeated U.S. Rep. Chip Cravaack was the favorite of 13 percent of Republicans, but he has signaled he is moving to New Hampshire to be with his family.)

A Franken-Bachmann matchup might be the most interesting from a spectator's point of view, and both have shown themselves to be prodigious fundraisers. Franken, however, would start with a distinct advantage. Only 35 percent of voters in the state have a positive opinion of Bachmann, compared with 59 percent who see her negatively, according to the survey.

"The desire of Minnesota Republicans to nominate Bachmann suggests they didn't learn much from their failures last year," the pollsters said.

Of course it's still early. At this time in 2007, Franken had yet to announce his 2008 candidacy. And when he won after a long recount, it was by scarcely 312 votes. But given his current standing versus Coleman, he's basically 6 points stronger than he was in 2008.

However the pundits slice it, Public Policy Polling concluded: "Al Franken does not appear to be among the more vulnerable incumbent senators next year."