With Weld County District Attorney Ken Buck likely to enter the 2010 U.S. Senate race, could illegal immigration really resurface as a hot issue during next year’s campaign? As district attorney for Weld County, where clashes over illegal immigration have won national attention, Buck received a lot of publicity for his strong opposing stance, including from The New York Times and PBS. He most recently made headlines as a defendant in a class-action lawsuit filed by the American Civil Liberties Union of Colorado. The suit alleges that Buck and Weld County Sheriff John Cooke violated privacy laws in searching and keeping thousands of people’s tax records in an effort to arrest illegal immigrants for identity theft. Such a hard stance against illegal immigration would likely help Buck among voters in a Republican primary. But many Republicans are wary about how it would play in the general election–especially among Latino voters, who have been a primary, but elusive, target of Republican wooing. There are conflicting reports about whether Buck has decided to run or not. The local newspaper in the small northeast Colorado town of Holyoke reported last week that Buck declared himself a U.S. Senate candidate at the Phillips County Republicans’ Lincoln Day soup, salad, and pie social. Also, several Republicans say Buck’s candidacy is a sure thing. Buck would only say to 5280 that he’s “out listening right now” and will make a decision sometime in April. Though he’s long been talked about as a potential candidate for Betsy Markey’s 4th Congressional District seat in 2010 and (more recently) attorney general, word that Ken Buck’s looking to the U.S. Senate came as a surprise even to many party regulars. If he runs, Buck has a lot of work to do. His name recognition is about nil outside of Weld County. He would have to start a statewide fundraising campaign, and he likely wouldn’t be able to attract a lot of out-of-state campaign cash. And at a time when Republicans are aching for a big GOP win following years of political defeat, some Republicans worry about Buck’s chances against Democratic incumbent Michael Bennet (or possibly Andrew Romanoff?). But people shouldn’t count out Ken Buck, simply because there’s been no Republican heavyweight who seems ready to run for Senate. The current list of potential GOP Senate candidates is composed of unknowns and the politically wounded: the most-talked about candidates, besides Buck, are Aurora City Councilman Ryan Frazier, radio talk show host Dan Caplis, and Bob Beauprez, who’s still recovering from his failed gubernatorial campaign in 2006. Colorado GOP Chair Dick Wadhams says the only person who could capture the Republican U.S. Senate nomination without a fight is former Colorado Governor Bill Owens–and Owens, Wadhams notes, isn’t interested in running. “This thing is wide open to anybody who wants to get in and work hard and win the nomination,” Wadhams says. So who would be a Ken Buck voter? He’ll get Republican support from Weld County. Plus, his visible stance against illegal immigration would likely appeal to GOP voters in Tom Tancredo Country: south Denver and Douglas County. Last year, Tancredo himself talked about possibly running for U.S. Senate. But Tancredo’s been mum for the past few months, and many Republicans cringe at the prospect of a Tancredo campaign alienating large swaths of Hispanic voters. Certainly, illegal immigration currently takes a back seat to the country’s economic problems, among other issues. But as Buck becomes more prominent, so too may be the issue for which he’s best-known.