COLORADO SPRINGS, COLO. --The biggest portrait in the office of Focus on the Family founder James Dobson--the best-known leader among America's 50 million-strong evangelical Christians--isn't of Jesus Christ. It's of Winston Churchill. "Churchill knew in '41 he could never beat Germany," says Dobson, rising to pull a biography of the master statesman from the bookshelf. "So his hope was to help the British people hang on until the Americans came." Dobson, helmsman of a multimedia empire--his radio show reaches nearly 2 million listeners daily and the volume of constituent mail to his organization requires a separate ZIP code--says it's a role he relates to. "For the last 20 years, all the centers of power have been influenced by a different worldview than what we share as evangelical Christians," he says, mentioning Congress, the judiciary, universities, and Hollywood as examples. "Our strategy has...