ST. PAUL, Minn. -- If Senator Al Franken decides to step down this week, amid harassment allegations, Governor Dayton would have to pick a temporary replacement.

Dayton would have to decide whether to appoint a caretaker for Franken's seat, or set up someone for a possible senate run in 2018.

"The governor has to decide, 'Do I want to appoint someone who will simply hold the office until the 2018 election, or do I want to appoint someone I hope is at the beginning of a long senate career'?" Steven Schier, retired Carleton College political science professor and political writer, told KARE.

Whoever's elected in 2018 would fill the final two years of Franken's current six-year term, and then face reelection in 2020 when Franken would've conceivably pursued a third term.

Most of the speculation surrounds Lt. Gov. Tina Smith who is Dayton's former chief-of-staff and trusted adviser. Smith has a background in business, politics and nonprofits such as Planned Parenthood.

The only wrinkle with appointing Smith is that the order of succession calls for the president of the Minnesota Senate to fill the post of Lieutenant Governor if it becomes vacant. That position is currently held by Sen. Michelle Fischbach, a Paynesville Republican.

"It's not clear to me Governor Dayton would encourage that partnership," Schier remarked. "And the governor also needs to think about his own health."

If Dayton would have to vacate the office before his term ends in January of 2019, and Fischbach were the Lt. Governor, the state would have a Republican chief executive.

Most of the other viable Democrats also hold elected office, and many of them are already running for governor in 2018. That group includes Congressman Tim Walz, State Auditor Rebecca Otto, former House Speaker Paul Thissen, former House Majority Leader Erin Murphy, and former St. Paul Mayor Chris Coleman.

Rachel Stassen-Burger, a longtime political reporter for the Pioneer Press and Star Tribune, said she expects to see a female appointee.

"I think probably, given the current atmosphere, he'd likely look to a woman," Stassen-Berger told KARE.

"You'd have to look at someone like Lori Swanson, the Attorney General, perhaps Lieutenant Governor Tina Smith, both Democrats, both women."

Attorney General Swanson has won three statewide races by impressive margins. She hasn't declared her intentions for 2018 yet, but is widely viewed to be considering a run for the top job.

"First of all, is Lori Swanson going to run for governor? Right? Because already Democrats are running for attorney general with the assumption she's running for governor," Schier explained.

If Dayton wanted to pick someone he already knows well, he might also consider former Human Services Commissioner Lucinda Jesson.

"Lucinda Jesson has not had a career in electoral politics, and the question is whether she would welcome the spotlight and possibly an electoral future," Schier said. "If Dayton went with Jesson it would probably be as someone to hold the seat, but not to run in 2018."

Congressman Keith Ellison's national profile in on the rise, as vice chair of the Democratic National Committee. But it's not clear how his popularity in his solid blue Twin Cities district would translate in a statewide race.

"The real question for Ellison is, how would he do statewide?" Schier said. "His district is significantly more liberal than the state as a whole, a certainly more liberal than Greater Minnesota, out state Minnesota."

Other names that have come up include House Minority Leader Melissa Hortman, Senator Patricia Torres Ray, former Senator Terri Bonoff, former Minneapolis Mayor RT Ryback and Rep. Peggy Flanagan, who is Rep. Walz's running mate in the 2018 governor's race.