Ronald Reagan’s presidency was a great success. He rebuilt a chaotic U.S. military and helped end the Cold War. Reagan’s radical tax cuts in 1981 spurred economic growth and redefined the relationship between U.S. citizens and their government. And he appointed conservative federal judges and bureaucrats who tried to roll back the half-century trend of expanded governmental control over our lives.

Reagan’s nice-guy charm made it difficult for even his critics to stay angry with him for long. But he was no mere smiling dunce, as liberal intellectuals used to snicker. His private papers and diaries instead reveal that he was widely informed, read voraciously, drew on a powerful intellect and was an effective writer.

It is no wonder that conservative leaders — especially the current crop of Republican presidential hopefuls — now constantly evoke Ronald Reagan’s successful presidency. In contrast, they rarely hearken back to the uprightness of the one-term Gerald Ford, or praise the foreign-policy accomplishments of the two Bush Republican presidencies.

Instead, the candidates try to “out-Reagan” each other by claiming they alone are the true Reaganites while their rivals in the primaries are too liberal, flip-floppers or without consistent conservative principles.

In short, Ronald Reagan has been beatified into some sort of saint, as if he were above the petty lapses and contradictions of today’s candidates. The result is that conservatives are losing sight of Reagan the man while placing unrealistic requirements of perfection on his would-be successors.

They have forgotten that Reagan — facing spiraling deficits, sinking poll ratings and a hostile Congress — reluctantly signed legislation raising payroll, income and gasoline taxes, some of them among the largest in our history. He promised to limit government and eliminate the Departments of Education and Energy. Instead, when faced with congressional and popular opposition, he relented and even grew government by adding a secretary of veteran affairs to the Cabinet.

Two of his Supreme Court appointments, Sandra Day O’Connor and Anthony Kennedy, were far more liberal than George W. Bush’s selections, the diehard constructionists, John Roberts and Samuel Alito.

Reagan’s 1986 comprehensive immigration bill turned out to be the most liberal amnesty for illegal aliens in our nation’s history, and set the stage for the present problem of 12 million aliens here unlawfully.

Republicans forget all this — but so do Democrats, who for their own reasons want to perpetuate an unflattering myth of Ronald Reagan as an extremist right-wing reactionary.

In foreign affairs, Reagan was not always sober and judicious. He shocked Cold Warriors by advocating complete nuclear disarmament at his Reykjavik summit with Michel Gorbachev.

In the middle of Lebanon’s civil war, he first put American troops into a crossfire. Then, when 241 marines were blown up, he withdrew them. That about-face, and the failure to retaliate in serious fashion, helped to embolden Hezbollah’s anti-American terrorism for decades.

The Iran-Contra scandal exploded when a few rogue administration officials sold state-of-the-art missiles under the table to Iran’s terrorist-sponsoring theocracy, and prompted opposition talk of impeachment.

In other words, a great president like Ronald Reagan made mistakes. He sometimes reversed positions, played politics and baffled his conservative base — some of the very charges now leveled against Mike Huckabee, Rudy Giuliani, John McCain, Mitt Romney and Fred Thompson.

When a candidate today says, “Reagan would have done this or that,” he apparently has a poor memory of what Reagan — the often lonely, flesh-and-blood conservative in the 1980s — was forced to do to get elected, govern and be re-elected. While in office, he proved more often the pragmatic leader than the purist knight slaying ideological dragons on the campaign trail.

So what is the real Reagan legacy? It is mostly the Great Communicator’s uncanny ability to distill complex problems, offer a more conservative solution than America was used to or ready for, and then inspire and enact difficult change through a brilliant “Mr. Gorbachev, tear down this wall” turn of phrase.

But 2008 is a different world from a quarter-century ago, when Reagan began his presidency. Amnesiac candidates need to separate the myth of Reagan — the perfect conservative — from the real man when stridently chastising their rivals for their past fudging on taxes, illegal immigration or the size of government.

The current pack of five serious Republican candidates should call on the spirit and principled inspiration of Ronald Reagan for guidance about new problems in the way they evoke Abraham Lincoln or Teddy Roosevelt.

But these candidates only do his memory — and their own careers — a disservice by claiming sainthood for Ronald Reagan, and thereby demanding a standard of immaculate conservative conduct that neither Reagan nor they could ever attain.