In talking about politics, people often move back and forth quite casually between references to "the Republican Party" and to "the conservative movement." Sometimes they are treated as almost synonymous, and, then again, they may be regarded as very different things -- almost rivals. Worst of all, many people seem to consider them a single big ball of wax, sharing the characteristics of both the party and the movement. For the sake of clarity, let us analyze them and distinguish them from one another.
The Republican Party is the much older of the two, having been founded in 1854 and fielded presidential and lesser candidates in every election since. The conservative movement, which is often and quite rightly defined more precisely as the "modern American conservative movement," didn't get under way, as a self-aware entity, until a century later, over a period of several years in the early 1950s. Among its early manifestations were the publication of Russell Kirk's "The Conservative Mind" in 1953 and the launching of National Review by Bill Buckley in 1955. There had been earlier manifestations of conservative opinions in American politics right from the start, but they rarely added up to a coherent body of related thoughts, and none managed to survive over a significant period of time.
The Democratic Party, of course, was even older, having emerged from the congeries of political alliances that characterized the nation's first quarter-century or so. And there have been leftist movements of one sort or another in American politics almost from the start. By the end of the 19th century, those of a socialist stripe were most prominent, and they have remained so ever since.
The two political parties have, at one time or another, encouraged many of these movements to seek fulfillment in supporting them. (Before the Civil War, for example, the Democratic Party was, in addition to much else, the political instrument of the slaveholding interests.) From their start -- but, above all, from the launching of Franklin Roosevelt's New Deal onward -- the leftist movements (to the extent that they have not founded parties of their own) have tended to support the Democratic Party. And from its inception the conservative movement has found its home with the Republicans.
What, exactly, is the relationship of the Republican Party to the conservative movement? I have found it useful to think of the Republican Party as a bottle, and the conservative movement as the wine it contains.
The bottle has little significance on its own; its importance lies in its contents. It is the vehicle for its contents, which could not maintain or promote themselves on their own. The party and the movement, in other words, need each other badly.
It is important to note, however, that the symbiosis between a particular party and a particular political movement doesn't necessarily last forever. The party can repudiate the movement, or the movement can walk out of the party -- as the Democrats ultimately rejected slavery, and the Progressives in 1912 walked out of the Republican Party.
At the moment, however, the Republican Party and the conservative movement still seem comfortably wedded. The marriage began in 1964, with the party's nomination of Barry Goldwater for president, and has lasted ever since. Many analysts assumed that the relatively liberal wing of the GOP would revive after Goldwater's crushing defeat and resume control of the party. But this never happened: Nixon's nomination in 1968 resulted from a decision by the conservative movement (albeit a bad one), and Reagan's election and re-election simply nailed down the alliance. Today, practically all Republican candidates proclaim their conservatism, and almost all conservative leaders vow their allegiance to the Republican Party. It has been a remarkably fruitful union.