A big recruiting coup for Senate Democrats:

Days after U.S. Sen. Jim Bunning filed a lackluster campaign finance report, a prominent Kentucky Democrat announced that he will run for the two-term Republican's seat.

"The people of Kentucky deserve a senator that has the vision, energy and record to help improve our state and country," Lt. Gov. Daniel Mongiardo said Monday in a written statement announcing his candidacy for the 2010 Democratic primary.

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Mongiardo said he will file the necessary paperwork later this week, setting up a possible rematch with Bunning, a 77-year-old baseball Hall of Famer. Bunning eked out a win in 2004 when Mongiardo, then a little-known state senator, came within about 23,000 votes of unseating him. Now with the improved name recognition, Mongiardo said he would be an even more formidable candidate.

Bunning, expecting to be targeted by both the state and national Democratic parties, has said he would need to raise about $10 million to win re-election to a third term. Bunning filed a campaign finance report last week that listed only $27,357 in financial contributions between Oct. 1 and Dec. 31. The report, filed with the Federal Election Commission in Washington on Wednesday, showed Bunning had $150,000 on hand.

According to The Fix, at least a couple other Democrats are also looking at the race, state Attorney General Jack Conway and state Auditor Crit Luallen -- though with Dan Mongiardo already having nearly knocked off Jim Bunning despite being unknown and underfunded suggests that he would be the strongest potential Democratic candidate this side of Congressman Ben Chandler. The only thing better than the strong Democratic bench? The fact that Bunning is reiterating that he will run.

Kentucky Sen. Jim Bunning doesn't seem to mind that on Monday he got a Democratic opponent in his 2010 race for re-election -- in fact, as of Monday evening he wasn't aware that Lt. Gov. Dan Mongiardo had entered the contest.

Told by a Politico reporter that as of today he had competition for his seat, Bunning replied: "I did? Who would that be?" Told of Mongiardo, Bunning exclaimed, "Really! I've been very busy."

Bunning, meanwhile, sought to clear up speculation that he was pondering retirement. "How many times do I have to say [I'll be running]?"

The Democrats' shot at winning this Senate seat would almost undoubtedly be better if Bunning were the GOP nominee than were he to retire. Indeed, with Bunning in the race, the contest probably even leans a bit towards the Democrats. That said, it isn't the case that Bunning dropping out will necessarily save this seat for the Republicans, as a strong, well-known and popular Democrat like Mongiardo places this race in or close to the toss-up category. In other words, regardless of whether or not Bunning seeks a third term in the Senate, this should be one of the upper tier races of 2010.