The Progressive Change Campaign Committee is asking for donations for Jesus "Chuy" Garcia.
The move suggests the former neurosurgeon is ready to take the presidential plunge.
The announcement sets up a fight between two of the most prominent Ohio politicians.
In new poll, the Wisconsin governor nearly doubles his next closest rival in the state.
The NRCC is pressuring top-targeted House Dems to vote for a veto override.
Instead of a prepared speech, Bush will sit for a Q&A with the conservative firebrand.
The Chicago mayor earned about 45.5 percent of the vote despite a big spending advantage.
Her speech suggested how she might look to make her gender one theme of a possible campaign.
Former Los Angeles mayor's decision makes Kamala Harris (D) a heavy favorite for open seat.
Former California Republican Party Chairman Tom Del Becarro has formed an exploratory committee for the seat, while Republicans continue to push former Rep. David Dreier (R-Calif.) to jump into the race as well.