  Jason’s post asked how the Republican party got to be the way it is and then approached the question of how its current composition makes sense today. As the historian in the bunch, I’ll see what I can do on the “how it got to be this way” question. Big businessmen (or corporatists) have been Republicans for a long time. The party always stood for the interests of industry. Past that, I’d point to three forces. The new deal drove small government/libertarian folks to the Republican Party. If you were for small government, you couldn’t be a Democrat. And with only two viable parties, that made the decision easy. The declining political importance of the civil war was another crucial factor. As the civil war receded in memory, Southern conservatives could increasingly choose their party rather than be Democrats by default. When the sixties came along, radical lefties and Republican strategy drove southern conservatives to the Republican Party. Radical lefties were bound to be Democrats because they favored the new deal and the ideology behind it. Radicals also favored pacifism, civil rights and other non-traditional cultural values. Republicans therefore had an easy time picking off southern social conservatives because southern social conservatives didn’t like the radical lefties and they were available.
All Republicans had to do was go easy on civil rights and advocate “law and order” (restraining hippies and blacks) and they got the South. Since most Southerners were Christian conservatives, they entrenched Christian conservatism in the Republican Party. This drew Christian conservatives, wherever they happened to live. The sixties also made it clear that hawkish folks should leave the Democratic Party. Radical lefties were Democrats and the horror of Vietnam tilted the rest of the party their way.
Prior to that, Democrats had been muscular folks, leading us into WWI, WWII, Korea and Vietnam. Since then, we’ve had a hard time coming up with a foreign policy strategy other than “war is bad… but we’re happy to support successful wars after the fact”. So Republicans had libertarians, hawks and corporatists. This doesn’t make much sense from an ideological perspective. Republicans are all against social spending, but that’s about all they agree on. It isn’t that they’re for social responsibility or individual responsibility. Social conservatives are all for an intrusive government and religious/social atmosphere that coerces people into making the “right” choices. Libertarians disagree completely. Corporatists aren’t really interested that much in these sorts of questions.
All this only makes sense from a historical perspective. Once folks of your stripe are in a party, path dependence takes over. It’s much easier to go along with the inertia and follow the rest of them to the party they’ve chosen. Years later, it may make little sense ideologically. But your group’s cash and muscle is already entrenched somewhere, why fight it? Mike 
