This fall's only congressional election, featuring a third-party conservative challenging the Republican nominee, tests the future of the GOP. Will the Tea Party insurgency prevail? Atlanta Pitting conservative purists against party pragmatists, a growing number of national Republican figures are bucking the party standard and backing a third-party candidate in the sole congressional election scheduled this year, upstate New York’s 23rd congressional district. Former vice presidential candidate Sarah Palin, former Senator Rick Santorum, former House Majority Leader Dick Armey, current Minnesota Rep. Michelle Bachmann, former Tennessee Senator and presidential candidate Fred Thompson, and former presidential candidate Steve Forbes have all...