RAND PAUL VS. THE BIG DOG…. We’ve recently seen a shift in Republican attitudes towards former President Bill Clinton. While the GOP tried to destroy the Big Dog not too long ago, much of the party has decided maybe he wasn’t so bad after all.

It appears, though, that the sentiment is far from universal.

Former President Bill Clinton campaigned for Attorney General Jack Conway in Lexington [Kentucky] on Monday, delivering a hard-nosed repudiation of Republican Rand Paul’s “radical ideas” to cut government spending.

Clinton touted Conway’s proposals for reducing the debt and creating jobs, while blistering Paul and Republicans for wanting to repeal programs such as loans for college students and new controls on big financial institutions — even as they push tax cuts for the rich.

“We have a practical, progressive, common-sense moderate who has actually done things and actually has a plan, running against a man with radical ideas and no record to back it up, no evidence that anything works that they’re advocating, who has embraced an agenda that will add a trillion dollars to the debt, not reduce the deficit and not create jobs, but let us go back to what got us in trouble in the first place,” Clinton said.

Clinton, named the nation’s most popular political figure in one recent poll, spoke on the lawn of University of Kentucky’s Administration Building at a rally designed to pump up enthusiasm for Conway.

There were any number of ways for Paul’s campaign to respond to this, including the option of not responding at all, which made it all the more interesting to see the Republican Senate hopeful choose the ugliest road possible.

“I’m not sure I would trust a guy who had had sexual relations with an intern. I mean, do you think he’s an honorable person?” Paul said at a campaign stop. “I think that’s disgusting. It gets to the point where we discount what he says.”

Really? Twelve years later, Paul thinks it’s sensible to play the Lewinsky card?

Look, Clinton was calling Paul out in a way that made the GOP candidate look bad — with observations that happened to be true — but to argue that Clinton’s affair leaves him permanently discredited is crazy, even by Paul standards. Indeed, it sets up a great opportunity to evaluate who has more credibility — the popular two-term former president who carried Kentucky twice, or the odd right-wing ophthalmologist with an extremist worldview and very little knowledge about the state he’s running in.

If Rand Paul wants to make this week about whether Bill Clinton knows what he’s talking about, I suspect Democrats would gladly oblige.

Steve Benen

Follow Steve on Twitter @stevebenen. Steve Benen is a producer at MSNBC's The Rachel Maddow Show. He was the principal contributor to the Washington Monthly's Political Animal blog from August 2008 until January 2012.