Former Republican U.S. Sen. Norm Coleman on Wednesday said he is leaving open the possibility that he may try to take on Gov. Mark Dayton in 2014.

Coleman told the Star Tribune that he would not run against Democratic U.S. Sen. Al Franken, who ousted him by a whisper-thin margin in 2008. But when asked about a gubernatorial run, he said, "I haven't ruled out other things."

First elected as a DFL St. Paul mayor 20 years ago, the former senator has long been a fixture in Minnesota politics and if he vied for Dayton's job, he would quickly attract national attention and cash. But Coleman, who joined the Republican Party in 1997, could be seen as too moderate by party activists and be forced into a primary.

Some GOP stalwarts are already saying they would welcome a more vigorous 2014 primary season, given how badly the Republican-endorsed candidate did against Democratic U.S. Sen. Amy Klobuchar last year and the still-indebted state of the Minnesota Republican Party.

Dayton, who won his 2010 race by fewer than 9,000 votes, has risen in Minnesotans' esteem as he has governed, according to recent polls. But he is still considered vulnerable to challengers when he tries to keep his seat next year. Dayton has said he plans to run again and has begun fundraising for the 2014 campaign.

Potential competition

Republican Hennepin County Commissioner Jeff Johnson is eyeing a gubernatorial campaign, and state Sen. Julie Rosen said Wednesday she continues to think about a possible run. Neither has the national reach or statewide name recognition that Coleman would have were he to enter the race.

While he lost to Franken, Coleman has still been busy in Washington. He leads the American Action Network and the Congressional Leadership Fund super PAC. He also is a lobbyist at Hogan Lovells in Washington and counts Minnesota's Medica among his clients.

During a brief interview Wednesday, Coleman said it was too soon to decide whether he will challenge Dayton next year.

"Folks are still trying to catch their breath" after the 2012 election, Coleman said. In 2010, his name was floated as a possible gubernatorial candidate, and it shook up the race when he finally decided that he would not enter that contest.

He said that he has never really seriously considered going up against Franken again.

"Things are too dysfunctional in Washington," Coleman said. "I don't see my future as serving in Congress."

Lately, the former senator has taken to Twitter to vent on the state of politics. He has bashed Republicans for voting against the fiscal cliff deal and criticized House members who tried to oust Speaker John Boehner.

"The harping from the cheap seats was meaningless," he said of those efforts. Sentiments like that have not endeared him to the Republican Party's more conservative wing.

Coleman said that if either U.S. Reps. John Kline or Erik Paulsen jump into the Senate race, it would immediately become competitive. He would not say whether he had talked to either of them to encourage them to run.

Kline and Paulsen have neither ruled out running against Franken nor officially expressed interest.

"While Congressman Kline is keeping all options on the table for 2014, he is currently focused on the pro-growth economic issues important to middle-class families and small businesses in the Second District," Kline spokesman Troy Young said.

Franken is planning to run for re-election and has raised more than $2.6 million for the campaign. He was first elected with just 42 percent of the vote and confirmed the winner only after a grueling, nine-month recount and election trial.

Since then, polls have found that more than half of Minnesotans approve of the job he is doing. No Republican has yet declared that he or she will run against him.

Rachel E. Stassen-Berger Twitter: @rachelsb