There never has been a need in the United States for a Christian political party because avowedly anti-Christian forces have been historically rare. Instead, we’ve had a continual alliance between moderate Enlightenment thinkers and Christians who have had similar agendas.
I sometimes wonder whether it is this coalition that is under more strain than the one between conservatives and libertarians that everyone talks about.
I also sometimes wonder whether the United States will ever see the emergence of a Christian Democrat party of the kind we see so frequently in Europe, though the U.S. version would surely be a tad more laissez-faire simply because of the American heritage. Such a party in the U.S. would be pro-life, pro-traditional family (through promotion rather than making alternatives illegal, probably), pro-modest welfare state tied to moral requirements, and soft on immigration. It would come down more or less in the center of American politics economically with a rightward tilt socially. I suspect it would also be typically pro-Israel given the sympathies of the great majority of American Christians.
There are a few fellows working on the Christian Democrat United States version on the web. For an interesting thought experiment as much as anything else, check ’em out at www.cdusa.org.