In a surprise announcement, Lt. Gov. Tina Smith said Friday she will not be a candidate for governor.

Smith, who served as Gov. Mark Dayton’s chief of staff before becoming lieutenant governor in Dayton’s second term, was widely expected to run next year to replace Dayton, who has said he will not seek another term.

In a Facebook post on Friday, however, Smith did not give a specific reason why she’d decided against running but said, “I never expected nor planned to serve in elected office.”

Smith joined Dayton’s ticket at lieutenant governor in 2014. She had previously served as his top aide, as well as the top aide to former Minneapolis mayor R.T. Rybak.

In an interview Friday, Smith said she considered running for governor for months. But after consulting with friends and family, as well as considering today’s political environment, she opted not to run.

“I would say that it is a difficult time in politics right now, but if anything that is a motivating factor, not a factor that dissuades me,” she said. “We need people in politics now more than ever are really ready to go out and fight for what they believe in.”

Smith said she will work hard to carry out Dayton’s agenda and do what she can to get another DFLer in office after him.

Democrats St. Paul Mayor Chris Coleman, state Rep. Erin Murphy, DFL-St. Paul, and State Auditor Rebecca Otto have also announced plans to seek the governor’s job.

On the Republican side, House Speaker Kurt Daudt and Hennepin County Sheriff Rich Stanek are still weighing whether to enter the race.