Lt. Gov. Tina Smith, one of the state's highest-ranking female elected officials and a close adviser to Gov. Mark Dayton, will not run for governor in 2018, throwing the race wide open for fellow DFLers.

Smith, 59, has been a top Dayton emissary, often traveling the state as she promotes the governor's agenda. Since early 2015, when Smith began her term, she has emerged as the state's most high-profile lieutenant governor, transforming the obscure role and often serving as the face of the Dayton administration. Her elevation from Dayton's chief of staff to running mate fueled speculation that she would run for the state's highest office.

In an interview Friday, Smith said she reached her decision after consulting with friends, family and political allies.

"As I have looked at everything, it's just really clear to me that the right thing for me to do personally is not to run," Smith said. "I feel very confident in that decision and actually really energized by being able to put all of my focus on the next, basically, two years left in the term and do this job that I really love."

The surprise decision comes as both DFL and Republican candidates are firming up plans to run for governor next year. Already, State Auditor Rebecca Otto; state Rep. Erin Murphy, DFL-St. Paul, and St. Paul Mayor Chris Coleman have announced plans to run. Other potential DFL candidates include U.S. Reps. Rick Nolan and Tim Walz.

On the Republican side, potential candidates include House Speaker Kurt Daudt, R-Crown; state Rep. Matt Dean of Dellwood, and Hennepin County Sheriff Rich Stanek.

Smith, while sipping camomile tea at the Black Dog cafe in Lowertown, said she considered how the electorate had shifted since the 2016 presidential election. Calling it an election that "turned everything on its head," she said the right candidate needs to articulate a message that will resonate with voters at a gut level.

"For me the most important thing is keeping a Democrat in the governor's office in 2018," she said, adding that, "I concluded that I have a path to winning in 2018. It's a difficult path. Nobody has a cakewalk to become governor."

She said her main reasons, however, were personal. She pledged to be active on the stump for DFLers during the race and she declined to endorse a candidate.

One outcome of her decision, Smith said, would be answering the open question of whether her role as one of Dayton's surrogates in budget deliberations would be tinged with gubernatorial politics.

"The dynamic of a campaign in 2018 hangs over a lot of people at the Legislature, and I will be really glad it doesn't hang over me anymore," she said.

Smith said she will continue her duties as lieutenant governor and has not set plans for after her term ends.

DFL Party Chairman Ken Martin reacted to the news with some disappointment.

"If she had chosen to run, she would have been a formidable candidate," Martin said. "She's been a great lieutenant governor."

As DFL candidates mull their runs, Martin said he expects the field to become crowded with strong contenders. "The biggest thing is to make sure we focus on an economic populist message and remind people that Democrats are on their side and that we're fighting for them."

Otto, who has begun campaigning to be governor, said she's confident Smith "will work as hard as she can to make good things happen for Minnesotans over her last two years." As for the impact on her own bid, Otto said: "All I can do is run my race and tell people why I am running."

John Rouleau, executive director of the GOP-aligned Minnesota Jobs Coalition, issued a statement on Smith's decision, calling it "a tacit admission that Minnesotans do not support the continued leftward lurch of Minnesota Democrats' failed leadership and aren't interested in four more years of the policies continuing to be backed by Democrats in St. Paul."

A message seeking comment from GOP Party Chairman Keith Downey was not returned Friday.

Smith, who graduated from Stanford University and earned an MBA at Dartmouth College, is a New Mexico native who moved to Minnesota in 1984 for a marketing job with General Mills.

She soon became entrenched in DFL politics, eventually serving as chief of staff to former Minneapolis mayor R.T. Rybak. Dayton met with Smith in 2010 at the urging of his ex-wife and top DFL political financier, Alida Messinger, who encouraged him to hire Smith as chief of staff.

Dayton and Smith have become political partners since she joined his nascent administration.

"To be able to have done both of these roles and to be able to do this role in particular with a person that is such a dear friend and political partner and somebody who is such a principled leader and someone who has given me the space to make the absolute most of this job, it's fantastic," she said.