Rep. Sean Duffy, R-Wis., is thinking of running for Sen. Tammy Baldwin's, D-Wis., seat in 2018, the Milwaukee Journal Sentinel reported.
Prospective candidates include Duffy, an early supporter of President-elect Donald Trump, Senate Majority Leader Scott Fitzgerald, R-Wis., and state Sen. Leah Vukmir, R-Wis.
Political operative Mark Graul told the Journal Sentinel "the names swirling around are very strong candidates," but it is almost impossible to predict candidates at this point.
"Right now, the most important thing for Republicans in Washington is to deliver on the mandate that they received from voters, and that will tell a lot about the kind of success they'll have in a general election," he said.
Fitzgerald told the Journal Sentinel in June "the party should unify behind" Duffy if he enters the race.
Duffy hopes to avoid a repeat of his brother Jeff's failed primary run in 2012. Former Gov. Tommy Thompson, R-Wis., won the GOP nomination, but he lost to Baldwin in the general election.
"There was a real opportunity last time that just kind of slipped away," Fitzgerald added.
Wisconsin GOP spokesman Pat Garrett told the Journal Sentinel "Wisconsin Republicans have a deep bench of highly respected candidates that will each give voters an alternative to Sen. Tammy Baldwin and her radical, out-of-touch voting record. Republicans are focused on issues that matter to Wisconsin families and will set a clear contrast to Baldwin's record of putting politics before people."