There's nothing really wrong with it, frankly. People of a given religion are no different than people of any other unified group with a particular set of values, like PETA, the ACLU, etc. People have gotten the idea that religious people can't take part in government and still remain religious.
There's nothing that says they can't, though. The government can't compel or dissuade you from worshipping God. You can't have a state-run religion, or a state-prohibited one. There's nothing that says we can't enact laws that reflect our moral heritage. Most of the ones we have already do.
So if Christians decide to band together and become a political force to be reckoned with, good for them. They've sat quietly and been battered around the head and shoulders by groups like NOW and other PACs that often oppose their views.