This Charles Krauthammer column has a pretty trenchant intro:
Major grumbling among conservatives about the Republican field. So many candidates, so many flaws. Rudy Giuliani, abortion apostate. Mitt Romney, flip-flopper. John McCain, Mr. Amnesty. Fred Thompson, lazy boy. Where is the paragon? Where is Ronald Reagan?
Well, what about Reagan? This president, renowned for his naps, granted amnesty to 3 million illegal immigrants in the 1986 Simpson-Mazzoli bill. As governor of California, he signed the most liberal abortion legalization bill in America, then flip-flopped and became an abortion opponent. What did he do about it as president? Gave us Sandra Day O'Connor and Anthony Kennedy, the two swing votes that upheld and enshrined Roe v. Wade for the last quarter-century.
The point is not to denigrate Reagan but to bring a little realism to the gauzy idol worship that fuels today's discontent.
You can't denigrate Reagan because he no longer exists. There's only Robo-Reagan, the better, stronger, faster, more conservative president that the Right has retroactively constructed and forced into the history books. But Reagan's flaws and shortcomings weren't necessarily his fault: You have to do something about immigration, and that will require some sort of earned amnesty for the 12 million undocumented immigrants living in the states. You can't outlaw abortion. You can't outlaw tax increases, of which Reagan passed many. You can't gut Social Security, which he tried, and failed, to do. Hardline conservatism just isn't very popular. Policy problems have their own logic, and their own demands. The Republican Base is demanding fealty to a platform that even Reagan, for all his formidable political gifts and advantages, couldn't hew to. His would-be successors, in office, will do no better.