What do you think of this statement: "Ronald Reagan was the first "conservative" president of the United States?"
What Professor Allen C. Guelzo of Gettysburg College meant by this is that earlier Republicans (save Lincoln) had no real ideology. McKinley, Taft, Hoover, Coolidge ... even Ike, despite that "military/industrial complex" thing, were basically on the side of the status quo, and the commercial interests that funded them. Lacking was a real ideology.
That came from Austrian émigrés like Fredrick Hayek, who had suffered their fill of European authoritarianism, and were convinced that only disaster could follow the stupidities of well-meaning idealism. Sorry, said fellow Austrian intellectual Leo Strauss, but with freedom comes inequality. And with attempts to temper inequality comes a loss of freedom.
Their ideology, in my opinion, suffered from an inability to understand that "freedom" entailed, and is informed by, economic freedom as well cultural freedom. But when it joined (and pandered to) a sort of "theo-conservativatism" that many Protestant working-class voters felt was more about religious culture than their own economic well-being, the combination boosted Reagan into power. Neo-conservatives - disciples of Hayek, et. al. - latched on to religious conservatism and the old status quo "paleo-conservatives" to create a force that elected most of our recent presidents. (And certainly tempered the politics of Bill Clinton, the lone Democratic exception.)
Guelzo wrote this stuff before the election of Barack Obama. But his final observation remains valid: Especially because the various varieties of conservatism remain often at odds with each other, the future of conservative ideology is still to be determined.