Steve Daines, a fifth generation Montana, announced Saturday he will challenge Sen. John Tester for re-election in 2012.
Daines, a Bozeman businessman, said he was challenging Tester because he has constantly voted with President Barack Obama.
"Jon Tester has made his choice," Daines said in announcing his candidacy. "He stands with Obama not Montana."
"I too have made my choice. I stand for Montana and not Obama," he said.
Daines was especially critical of Tester for voting in favor of President Barack Obama's health care reform.
Tester, a Big Sandy organic farmer, has not announced whether he will seek a second six-year term, but it is widely anticipated he will.
Daines is the first Republican to announce his candidacy. Rep. Denny Rehberg has been mentioned as a possible Republican\candidate, but he has not said if he will run,.]