U.S. Rep. Ken Buck, R-Windsor, talks about tax reform in Washington at a barbecue near the Capitol Tuesday. (Photo by Marianne Goodland/Colorado Politics)

U.S. Rep. Ken Buck gave his most definitive answer to date on whether he will run for re-election in Eastern Colorado’s 4th Congressional or seek to become the state’s top prosecutor.

Buck and state Rep. Cole Wist of Centennial have been the favorites to jump in the GOP primary for attorney general, but only if incumbent Republican Cynthia Coffman opts for the governor’s race.

Back in July, Mark K. Matthews of the Denver Post quoted Buck in Washington regarding Coffman:”If she decides that she’s not going to seek (the) attorney general’s office, I would certainly keep my options open.”

Last week on the radio in Denver, Buck sounded like options had closed.

“Right now, I think it’s very unlikely that I do anything other than stay focused on running for the 4th Congressional District and doing the job that I enjoy doing here in D.C.,” he told Ross Kaminsky on KHOW 630-AM.

That’s not ironclad, by any means, but it’s only slightly more forceful than what he told Colorado Politics’ Marianne Goodland just a couple of weeks ago.

Buck said then he was focused on his congressional race,  “because Cynthia Coffman is running for attorney general. If anything changes I’ll let you know.”

So does he know more now than he did then? He’s not saying.

As you would expect, his Democratic challenger, Longmont veterinarian Karen McCormick, is calling flagging Buck for political opportunism.

“Coloradans deserve a leader who cares about the issues more than they care about their career, and as the representative of Colorado’s 4th Congressional District, I will make sure that everybody in our district knows they have a seat at the table when we’re making decisions,” she said in a statement Friday, calling out Buck for his less-than-definitive remarks on the radio.

Meanwhile, Coffman and state Treasurer Walker Stapleton are widely discussed as possible entries into an already crowded GOP primary. They are the most interesting partly because they are two of the state’s highest-ranking Republican officials (with Secretary of State Wayne Williams, who is not exploring the governor’s race, though many wish he would), but also because they share many of the same would-be donors and supporters.

While Republican insiders say they have no idea what Coffman plans to do, Stapleton is all but certain to enter the race, and you can expect Colorado Politics to break the news of that major announcement.