I think the advantage social conservatives may have is on the "local" level -- state posts, Congressional office, and governors and senators in certain states that have homogenous demographics.

But on a more "national" level (president, senate and govs in less homogenous states), I think social conservatives can hamstring the conservative movement. And, yes, I realize a lot of this is dictated by the press, but to the average voter perception is reality. Unfortunately a lot of people are dumb enough to believe what is reported to them on the NBC News or Good Morning America.