KIRK DISCOVERS HOW WRONG HE WAS (WHEN HE WAS RIGHT)…. On June 27, Rep. Mark Kirk (R) of Illinois was one of just eight House Republicans to break party ranks and support the American Clean Energy and Security Act (ACES), which included a cap-and-trade system. Far-right activists, who don’t accept the evidence of global warming, vowed revenge.

On July 27, Kirk, now a candidate for U.S. Senate, sure is sorry about upsetting those right-wing opponents of climate-change legislation.

Kirk immediately drew flak from the state’s Republican base over the vote, which nearly prompted a primary challenge from his own party chairman, Andy McKenna.

But in an interview with FOX Chicago Sunday, Kirk sounded a lot more like a “drill-baby-drill” type of Republican than one focused on the environmentally-minded constituents in his North Shore Chicago district.

“I’ve always backed energy independence policies, but I’ve heard from people on this issue like no other. The energy interests of Illinois are far broader and deeper than my North Shore district. The political prospects of this bill are dim in the Senate…. I think the bill in its current form is probably dead,” Kirk said.

“What I really want to see is a new round of nuclear power plants for the country, exploration for oil offshore and the Trans-Canada pipeline that would bring lower-cost natural gas to the Midwest.”

What a difference a month — and a bunch of right-wing vitriol — can make. A month ago, Kirk was positioning himself as a moderate, willing to make the tough choices to combat a climate catastrophe.

A month later, his support for the bill he just voted for has vanished, and Kirk is carefully repeating the conservative line on energy policy.

Imagine that.

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.