Minnesota's suddenly available U.S. Senate seat proved tantalizing Friday for people considering a move up the political ladder and presented challenges for Gov. Mark Dayton as he decides who will get the job at least in the short run.

The two-track maneuvering was in full swing a day after Democratic Sen. Al Franken announced his impending resignation under pressure tied to multiple allegations of sexual misconduct, many of which he denied. Franken hasn't given a departure date yet, but his resignation will leave Dayton to pick a fill-in, who would be guaranteed to serve only until voters decide the next senator in a November special election.

Dayton made his first comments on the vacancy without revealing who is being considered for appointment. He told reporters at an event in Minneapolis that he's looking for a "great senator" and "there are a number people who fit that bill."

Much of the speculation has been on Lt. Gov. Tina Smith, a trusted adviser to Dayton who has previously held top jobs under former Minneapolis Mayor R.T. Rybak and former Vice President Walter Mondale. She had thought about running for governor in 2018 but decided against a bid.

If Dayton did pick Smith -- she's not the only person under consideration -- it could further roil Minnesota's already choppy political waters. State law provides that the Senate president would fill the lieutenant governor post during Dayton's final year in office; Republican Sen. Michelle Fischbach of Paynesville holds the title presently in a Senate her party controls by a single seat.

Senate Majority Leader Paul Gazelka, R-Nisswa, said Friday that he has briefly discussed with Dayton the possibility Smith gets named and a potential workaround to head off a 33-33 Senate. Replacing Fischbach with a Democrat merely for succession purposes could require a special session. It would also ease fears of some Democrats who worry about full Republican control of state government if the 70-year-old Dayton can't complete his term.

“If we can figure out how to do it in a way that allows the governor have his pick and have a Democratic lieutenant governor, we’re open to having that conversation," Gazelka said, adding, "Obviously we are interested in keeping our majority."

Gazelka said lawyers are exploring whether succession is mandatory or the elevated lieutenant governor could remain in Senate for a time.

Dayton wouldn't comment on that situation.

"All things are floating around. I'm not going to comment anymore on the particulars," Dayton said. "It's all speculative, and I'll have an announcement in a couple of days."

Meanwhile, people who could make a run for Senate were making their interest -- though tentative -- known.

Among Republicans, former Gov. Tim Pawlenty declined to rule out a return to politics while resting on a catchphrase he often uses of being "politically retired."

"But like everybody else I’m thinking about all the challenges and troubles our country is facing and asking what can I do to make it better. And I don’t know if that means returning to public service," Pawlenty said before a speech to the TwinWest Chamber of Commerce in St. Louis Park, one of many such events he’s appeared at in recent months.

Gazelka said he hasn't slammed the door shut either, though he said it was less likely than more that he'd run. "I guess it's fair to say I'm not ruling it out but I really believe what I'm doing of the leader of the Senate is really important for Minnesota," he said. "It's not 100 percent ruling it out."

State Sen. Karin Housley, R-St. Marys Point, said she is giving the race serious consideration. Many others are as well, including former Senate Majority Leader Amy Koch. The state Senate is not on next year's ballot so no incumbent senators need to give up their seats to wage a bid.

It's possible that candidates in Minnesota's crowded race for governor could switch courses, too.

Few Democrats have publicly tossed their names forward, but the party also has a bounty of gubernatorial candidates who could make a shift.

State Sen. Scott Dibble, DFL-Minneapolis, said he has been approached about running. "I'm keeping my options open," he said.

Sen. Melisa Franzen, DFL-Edina, was thinking it over, too. "It needs to be a thoughtful decision, and I am having that thoughtful discussion and seeing if that’s something I'd be interested in pursuing," she said.

State Sen. Patricia Torres Ray, DFL-Minneapolis, was more overt about wanting the job -- but only if Dayton picks her. "I would not be interested in running if the governor is not interested in appointing me," she said.

Her comment reflected another tension point around the vacancy. Some national Democrats hope Dayton picks someone who pledges to run next year, giving the party an incumbent with a head start and potentially minimizing a divisive primary. Some advisers to Dayton have urged him to select a caretaker senator, expressing concern that staging a 2018 candidate wouldn't be favored by voters and could hurt the party's entire ticket next fall.

No matter what, the race will be a sprint by current standards. That means candidates must decide soon to start building backing within their parties and, more importantly, raising cash. With 47 weeks before the next election, the pressure to build up a campaign account will be intense. If the race costs each party nominee $15 million -- a low number in recent times for competitive Senate races -- that means raking in more than $300,000 a week for a candidate who starts now.