Kentucky's junior senator couldn't raise much money for his campaign, didn't have the support of the state's senior senator, fellow Republican Mitch McConnell, and was widely panned in D.C. and Frankfort for being an ineffective legislator.
And he was better known for mean-spirited comments about Democrats, especially his opponents, than for any piece of legislation he ever sponsored.
Other than those things, he had everything going for him - not.
The truth be known, national and state Republicans probably are a lot happier about Bunning's move than national and state Democrats.
For the GOP, Bunning's departure cleared the way for the Republican Secretary of State Trey Grayson to run. Grayson, who had raised twice as much money for his exploratory campaign as Bunning did for his real campaign, had held off entering the race out of loyalty to his fellow northern Kentuckian.
And it was obvious Grayson was chomping at the bit to enter because not long after Bunning said he was heading to the showers, he announced he was running to the mound.
A 'rising star'
Grayson is the personification of the over-used phrase, "rising star." He really is one.
He has received high marks from Democrats as well as Republicans and, most importantly, from average Kentuckians, for the way he has served as secretary of state, especially for several innovations to help county clerks do their jobs and voters cast ballots.
He is dynamic but not in an in-your-face way. He's personable but not a glad hander. He is not a lectern pounder, but he's an effective speaker. He generally lets his accomplishments speak for him.
And he showed that he can be independent by openly criticizing Ernie Fletcher as the then-Republican governor kept denying the obvious patronage scandals that rocked his administration. Grayson spoke out while McConnell kept quiet, the state's GOP godfather preferring to let his silence over Fletcher do his talking.
The lone obstacle to Grayson's path to the Republican nomination is Dr. Rand Paul, son of former GOP president candidate Ron Paul. Rand Paul, a self-styled anti-tax "libertarian Republican," is not to be taken lightly. He has raised a fair amount of cash and apparently has developed as rabid a following of conservatives in parts of Kentucky as his dad did in parts of the country.
Also, there is still talk that Senate President David Williams might enter the race. He would be a formidable opponent for Grayson but would be an underdog like Paul.
While Grayson's entry in the race has brought smiles to once-frowning Republican faces and has caused Democrats to put the champagne back into their refrigerators at least for a while, the Dems may be a tad sad but they feel they still have a solid chance at winning Bunning's seat.
The party has two strong and pretty dynamic candidates of their own running in the primary - Attorney General Jack Conway and Lt. Gov. Dan Mongiardo.
Conway isn't a rising star. He's a shooting star. He's only been in state office two years and he already has set his sights on D.C.
And Mongiardo would be in D.C. now, running as the incumbent, had it not been for ultra-conversative Democrats in western Kentucky who turned back a Mongiardo tidal wave that had washed over much of the rest of the state and gave the race to Bunning in the 2004 general election.
So a Grayson-Conway race or Grayson-Mongiardo match-up would be tough, and it certainly would be foolish this early to predict an outcome.
But one thing is for sure. With Bunning out and Grayson in, the chances of the GOP holding onto the Senate seat are lot better now.
Republicans are a lot more hopeful and Democrats a lot less optimistic than they were before the incumbent left the mound for good.