Democratic Senatorial Campaign Committee Chairman Jon Corzine (N.J.) said Wednesday that “there is a fitness issue” surrounding the re-election of Kentucky Sen. Jim Bunning (R), publicly voicing what to this point largely had been a whisper campaign about the Republican’s health.

“Senator Bunning has raised so many questions about his ability to serve the people of Kentucky well,” said Corzine. “It’s his own behavior at stake here.”

The DSCC released a new ad Wednesday that features video with Bunning’s recent comment that he doesn’t “watch the national news or read the paper.”

The commercial’s narrator says that by ignoring current events, Bunning probably missed the 79,000 Kentucky kids without health care or the 49,000 jobs lost in the state.

The ad features excerpts from editorials from local papers that say Bunning “shortchanged Kentucky” and is “divorced from reality.”

The Bunning campaign has studiously avoided answering questions about his health, though he did release letters from several doctors proclaiming he is in fine shape. Bunning did not release his full medical records, however, as Democrats had requested.

Seeking to show voters he is more than competent to represent them, Bunning, 73, is currently on a five-day bus tour of the state with Senate Majority Whip Mitch McConnell (R-Ky.).

Regardless of Bunning’s recent burst of campaign activity, the DSCC smells blood and has spent more than $1 million in coordinated dollars and independent expenditures on behalf of the Democratic nominee, state Sen. Dan Mongiardo.

“We like the momentum in this race tremendously,” said Corzine. “We are sending a clear signal that we think this is a winnable race.”

The National Republican Senatorial Committee has not run any ads in the state and has no plans to do so, according to knowledgeable sources.

Dan Allen, communications director at the NRSC, scoffed at the DSCC’s investment.

“It is going to be a nightmare for them to spend upwards of $1 million and end up losing,” Allen said.

Republicans privately acknowledge that the race has tightened considerably due in large part to Bunning’s gaffs on the campaign trail, including his admission that he used a TelePrompTer for his opening and closing statements during a recent debate with Mongiardo, who was at a different venue for their televised contest.

But they argue that Bunning’s numbers are now bouncing back as he ends the campaign by closely tying himself to President Bush while simultaneously linking Mongiardo to Massachusetts Sen. John Kerry (D).

“Bush-Bunning is going to win this state,” said a senior adviser to the Senator. Internal polls on both sides show Kerry running in the mid to upper 30s in Kentucky. In the 2000 presidential election, then-Vice President Al Gore — who came from neighboring Tennessee — won 41 percent in the Bluegrass State.

Republican insiders say that Bunning has a high single-digit lead over Mongiardo in recent internal GOP polling; Mongiardo pollster Fred Yang had the race at 44 percent for Bunning to 43 percent for Mongiardo earlier this week.

Another factor in Bunning’s favor is a ballot measure seeking to ban gay marriages in Kentucky. Polling shows that more than three-quarters of the state’s voters support the initiative, which is likely to drive conservatives to the polls.

“I give them an ‘A’ for effort, but at the end of the day it ain’t going to happen,” the Bunning aide said.