Democrat Rick Weiland’s recent announcement to run for Senate leaves one massive question in the South Dakota race: Will former Rep. Stephanie Herseth Sandlin, D-S.D., run too?

With Weiland in, the potential for a high-profile primary between Herseth Sandlin and the son of retiring Sen. Tim Johnson appears to be over. Weiland and Ryan Casey, the head of the Draft Brendan Johnson for Senate movement, both told the Sioux Falls Argus Leader that they no longer believe Johnson, a U.S. attorney in South Dakota, is interested in seeking his father’s seat.

But Johnson supporters are already being encouraged to back Weiland, which means the potential for a competitive primary remains.

(See also in Roll Call: Senate Race Recruitment: Too Early to Fail?)

Herseth Sandlin said in a statement to the newspaper that anyone and everyone is welcome to join the race, but she remains undecided. “Obviously, I have both professional commitments and family obligations to consider.”

Steve Murphy, who served as Herseth Sandlin’s media consultant in 2010, told CQ Roll Call he is not aware of the former congresswoman’s plans.

“Stephanie is the best candidate and would have a solid chance of winning,” Murphy said. “She has terrific numbers and even better skills.”

A Democratic operative said the potential for a conservative challenge to former Gov. Mike Rounds in the Republican Senate primary “affords Democrats some time to see how everything shakes out on their side.”

It wouldn’t be the first time Herseth Sandlin faced a Weiland family member in a primary.

Weiland lost to Herseth Sandlin in the 2002 Democratic primary for the state’s at-large House seat, 58 percent to 32 percent. They were running for the open seat of then-Rep. John Thune, a Republican making his first bid for Senate that year.

In 2010, Weiland’s brother Kevin Weiland, a physician, briefly challenged the congresswoman in the primary before opting against it. Kevin said he was motivated by Herseth Sandlin’s vote against the health care overhaul. The congresswoman went on to lose her seat to now-Rep. Kristi Noem, R-S.D., in the general.

In Rick Weiland’s first bid for Congress, he lost to Thune in the 1996 House race to replace Tim Johnson, who ran for Senate. Thune won 58 percent to 37 percent.