Louisville businessman Matt Bevin is set to announce later today that he will challenge Senate Minority Leader Mitch McConnell (R-Ky.).

And McConnell is wasting no time attempting to define Bevin.

McConnell's campaign is up with a new ad buy labeling his primary opponent "Bailout Bevin" and noting that Bevin's business -- which is based in Connecticut -- accepted $200,000 in bailout funds. Bevin sought the funds after his business, a bell factory, burned to the ground.

Meanwhile, Bevin's campaign will launch its own ad later today.

The "B" word has generally been a scarlet letter in Republican primaries -- particularly when it comes to members who voted for the Troubled Asset Relief Program (TARP) bailout in 2008. Those members include McConnell -- something Bevin's campaign is likely to use against the leader.

In response to McConnell's ad, the Senate Conservatives Fund, which hasn't backed Bevin but has suggested McConnell should step aside in favor of a more electable candidate, went after McConnell.

"It's the height of hypocrisy for Mitch McConnell to attack anyone on bailouts when he was the one who voted with Barack Obama to bail out the Wall Street banks," SCF spokesman Matt Hoskins said.

McConnell's campaign has dismissed the wealthy Bevin as a "nuisance" but appears to be taking no chances.

Bevin is set to announce his campaign at 10 a.m. Eastern. The launch will be followed by a three-day tour of the state.

Updated at 9:59 a.m.