A showdown between the Texas governor and Michele Bachmann could determine where the Christian vote will go The battle for the “Bible belt”, one of the most crucial constituencies in the Republican White House race, will begin in earnest in Waterloo, Iowa, where Texas governor Rick Perry, who announced his candidature , is to speak at a dinner in the Electric Park ballroom that will also be attended by congresswoman Michele Bachmann. Bachmann changed her diary to be there, setting up an early showdown between two Christian evangelicals who may well determine the identity of Barack Obama’s opponent in the presidential election next year. The importance of the evangelical vote is huge, representing an estimated 40% of Republicans who will vote in the Iowa caucus, which is scheduled for February. Iowa, as the first of the contests, matters – helping to propel candidates to the front of the race and seeing others heading for oblivion. Bachmann has received the endorsement of more than 100 pastors and Christian leaders in the state in the past week alone. But Perry’s entry upsets her calculations. He is both a politician and part-time preacher, the kind of southerner who appeals to the Christian right. “Perry’s entry shifts the dynamic,” said Steve King, a rightwing congressman from Iowa, who was speaking at the Iowa state fair, where a string of Republican candidates used soapboxes to address voters sitting on straw bales. King is close to Bachmann but said he would not endorse anyone until after Labour Day, on 5 September. Other Republicans in the race such as Rick Santorum, Tim Pawlenty and Herman Cain have made bids for the Christian right, but it is Bachmann who appears to have won them over with her extreme anti-gay rhetoric and strong views on abortion and other social