Scott Romney, GOP presidential candidate Mitt Romney’s brother, is looking at running for retiring Democratic Sen. Carl Levin’s seat, according to a Michigan GOP source with first-hand knowledge of his interest.

The Republican is a Harvard-educated corporate attorney at the Detroit-based law firm Honigman Miller Schwartz and Cohn, LLP. He was not immediately available for comment.

On the Democratic side, Rep. Gary Peters told The Detroit Free Press editorial board that he is “going to seriously consider” running. Peters, who ended 2012 with nearly $500,000 in cash on hand, is considered the Democrats’ top recruit.

It has been a topsy-turvy day in Michigan politics, as candidates have floated their names in and out of contention. Levin announced Thursday that he would not seek a seventh term next year.

Democrats begin the open-seat race with a decided advantage. But serious structural problems plague the Michigan Democratic Party. This race, along with the 2014 gubernatorial campaign, will test newly-elected Chairman Lon Johnson.