Minnesota Gov. Mark Dayton is expected to appoint his lieutenant governor and close ally, Tina Smith, to Al Franken’s seat if the Democratic senator resigns on Thursday, three people familiar with the Democratic governor’s thinking said.

But that appointment would be just the start of an upheaval in Minnesota. Part of the reason Smith could be heading to the Senate, the sources said, is that she has indicated no interest in running for Congress in the past and would not run for the remainder of Franken’s term, which expires in 2020, in a 2018 special election. That would clear the way for a wide open Democratic primary next year if Franken steps down.