Ross, Douglas, Kathleen, Jim, and Christine,
These entries are so smart that I don't have much to add, apart from the obvious: The various Republican constituencies need some reason to hang together. It's not obvious what socially conservative, big-government types like Mike Huckabee have in common with economically conservative libertines like Rudy Giuliani. So why are they in the same party? It used to be because they both hated communism. Then it was Bill Clinton. Most recently, it was a shared fear of Islamic extremism. What now? Time to think of something—quick. There's no natural reason these two groups should be connected. In fact, they sort of despise each other, as you'll notice immediately if you ever eat with them.
Once the party figures out what it's for—or more precisely, against—it ought to stick to its story. People respect principle, even if they disagree with it. That was Ron Paul's secret. (The gold standard? Who's for that? Didn't matter. Paul seemed like he sincerely was.) Let's say you spent decades extolling the genius of the free market, then, the moment an economic crisis struck, your first instinct was to swoop in and nationalize entire industries.
People might begin to suspect you weren't really sincere in the first place. They might also wonder if you ever really understood your own policies. You could lose an entire election over something like that.
Finally, after the party has settled on what it believes, it ought to go shopping for a leader. I recommend someone who speaks fluent English. This matters, it turns out, and not just for aesthetic reasons. In a democracy, eloquence is a basic condition of leadership. A president has a moral as well as a political obligation to explain his program. His constitutional powers are limited to just a few (war, the veto). His real authority comes from persuasion.
It helps if you can talk.