(CNN) -- If presidential hopeful Rick Perry should awaken one night in a cold sweat with the Ghost of Republican Past hovering by his bedside, the apparition will likely take the form of Sen. Charles Percy, who passed away on Saturday after a long struggle with Alzheimer's disease.





Percy's political career ended when he lost his Illinois Senate seat in 1984, the same year that future Texas Gov. Rick Perry won his first election to the Texas House of Representatives as a Democrat. Charles Percy's fall from GOP wunderkind to party outcast offers a vivid illustration of the Republican Party's mutation from a vibrant and diverse coalition to the dogmatic cult of conservative ideology that it has become today.





In 1968, political gossips buzzed about the possibility that the rich, handsome, "All-American" Charles Percy might run for president. The New York Times called him "the hottest political article in the Republican Party," and Richard Nixon worried that Percy would be his most formidable competitor in the primaries.





Percy was a moderate-to-liberal Republican from the Rockefeller wing of the party who had made his name promoting affordable housing and combating urban poverty. Such positions were seen as positive political attributes in 1968. Four years earlier, Barry Goldwater's libertarian presidential campaign had proved a disaster, and Republicans were not eager to repeat the experience.





But Percy chose not to run and instead endorsed his colleague Nelson Rockefeller, who lost to Richard Nixon. Over the next few years, Percy clashed frequently with Nixon over defense spending and Supreme Court appointments. During the Watergate scandal, he again defied Nixon by demanding an independent investigation.





With his popularity and national name-recognition peaking, Percy might have had another shot at the presidency in 1976, but he deferred to the incumbent, Gerald Ford. There would not be another chance, for the Republican Party was moving away from Charles Percy.





In the mid-1970s, a group of conservative insurgents known as the New Right began plotting to extinguish the party's liberal wing. They despised men such as Percy and embraced a fanatical brand of social conservatism. One of their leaders, Paul Weyrich, founded the Heritage Foundation and recruited Jerry Falwell to lead the Moral Majority.





One by one, the New Right knocked off the liberal Republicans, either by defeating them in primaries or fatally weakening them in general elections -- names now barely remembered such as Clifford Case of New Jersey or Edward Brooke of Massachusetts.





In 1984, New Right leaders backed a primary challenge against Percy. When that failed, they endorsed his Democratic challenger, the liberal, bow-tie wearing Paul Simon. One of the leaders, Richard Viguerie, explained that Percy's defeat was more important to conservatives than retaining Republican control of the Senate. When the voting was over, the Republicans kept the Senate, but they lost Charles Percy.





The drive for ideological purity has continued ever since, with tea party groups and fundraisers such as the Club for Growth targeting moderate conservatives after the liberals went extinct. In recent years, they helped force out Arlen Specter of Pennsylvania, Lincoln Chafee of Rhode Island and Charlie Crist of Florida.





Perry, the front-runner of the Republican presidential field in polls, is a deep social and fiscal conservative who would never have had a shot at the presidential nomination in 1968. But in 2012, it's the liberal Charles Percy who wouldn't have stood a chance. Even Goldwater's refusal to embrace the religious right would doom his candidacy were he to run today.





Yet perhaps Perry would still be wise to pay attention to the Ghost of Republican Past.





He might get to see the old Democratic Party advertisement showing a disembodied pair of hands ripping apart a Social Security card. That advertisement helped turn the tide against Goldwater, who like Perry had challenged Social Security.





Conservative activists have succeeded in driving American politics far to the right, but there may still be limits.





The opinions in this commentary are solely those of Michael Wolraich.
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