Boy, I'd hate to be part of the republican leadership right now, faced with trying to piece together a fractured party. It's always been an uneasy alliance between the religious right and big business/fiscal conservatives, but this year the cracks have turned into a chasm. The wealthy and well educated could give a rats ass about gay marriage. The poor could care less about tax breaks on capital gains.
I see two ways they can rebuild. The first is that Mike Huckabee or someone similar makes a serious play for the party in 2012. He's got religious credentials, but is less fiscally conservative, because he believes in that "be my brother's keeper" stuff. I think it will play to the center well, especially with the economy tanking. People are tired of wars, tired of trickle-down economic bullshit - if he can moderate the 'values' message a little to appeal to the middle, he could have a shot.
The other route, combining centrist social values with fiscal conservatism is more likely, in my opinion. Here's why_ The GOP is losing young voters, and the base of their party at a phenomenal rate. In just eight years, they've gone from a 48/48 split (Gore/Bush) to a 66/32 split between Obama/McCain. Also consider that Prop 8, banning gay marriage in California, was opposed 66 to 34 by young voters.
It's just unsustainable to build a party on wedge social issues like gay rights. Change is going to happen eventually, so their party would do well get out ahead of it. (comparisons to the civil rights movement in the 60's seem apt). Leading this side, think of people in the Mitt Romney mold_ Unafraid of gay marriage (at least until he had to run for the current GOP's nomination), but fiscally conservative and pragmatic. See, religious dogma has a way of hampering a politician's ability to build coalitions through compromise. They'll still get a grudging evangelical vote, but can focus on playing to the center instead of to a shrinking (and increasingly out-of-touch) right.
Either way, this election has proven that the real base of power is in the grassroots, in the working class, and in 5 and 10 dollar donations from millions of people. Until the GOP finds a face for the party who can connect viscerally with this part of the electorate, as Obama did, they'll continue to be an opposition party.