When President Obama lifted Bush-era restrictions on federal funding for stem-cell research, he was changing more than a policy. He was changing a mindset, a whole approach to government.

Too often during the previous administration, policy was determined by what the president WANTED to be true, what he thought SHOULD be true. But often reality intervened, overwhelming ideology. The 43rd president did not heed the wisdom of the second president, John Adams, who addressed the issue of reality in 1770, 27 years before he succeeded George Washington.

As a young lawyer, defending British soldiers in a Boston courtroom, Adams declared: "Facts are stubborn things; and whatever may be our wishes, our inclinations, or the dictates of our passion, they cannot alter the state of facts and evidence."

The 44th president, however, is listening to Adams. He's dealing with the world as it is, not how he wants it to be. As he reversed Bush's policy on stem-cell research, Obama also issued a directive emphasizing the importance of unfettered scientific research. The goal, he said, "is about ensuring that scientific data is never distorted or concealed to serve a political agenda and that we make scientific decisions based on facts, not ideology."

The clash between facts and ideology often appears as a tension between science and religion. But in other cases, political rather than sectarian imperatives clouded the Bush administration's appreciation for reality.

Take Iraq. The president was told repeatedly that invading that country would unleash tribal rivalries and violent instability. But he wanted to believe that American troops would be greeted as "liberators" and that "democracy" would solve everything. The cost of his miscalculation so far: more than 4,200 American deaths and more than $600 billion in taxpayer money.

This question of mindset, of how to approach the job of governing, was central to Obama's victory last November. He did not win because the country suddenly swung leftward. Only 22 percent of the voters called themselves liberals, virtually the same percentage as four years before and 12 points lower than the number of self-identified conservatives. But moderates who do not identify strongly with either extreme comprised 44 percent of the electorate and backed Obama by three to two.

In congressional elections, these moderates practically wiped out Republican representatives in New England and New York and elected new Democratic senators from Oregon to North Carolina.

No wonder Democrats are so thrilled at the rise of Rush Limbaugh as a dominant voice in GOP circles. He's a gift from the political gods, a living, breathing embodiment of the ideological bluster that moderates disdain about the Republican Party. With Bush retired to Texas, his rivals need a new demon; if Rush were not on the radio, Democrats would pay to put him there.

Not only did the Republicans ignore John Adams; they ignored John Danforth, a moderate Republican senator from Missouri for 18 years. He's also an Episcopal priest, so he had some credibility when he warned against the rising influence of conservative Christians.

Religious people have always engaged in political action, he noted. Moses confronted pharaoh, and clergymen marched for civil rights. The problem, he said, "is with a party that has gone so far in adopting a sectarian agenda that it has become the political extension of a religious movement."

The best example of that "sectarian agenda" was the party's position opposing stem-cell research, Danforth said. Republican policies favored one faith over another and "would punish people who believe it is their religious duty to use science to heal the sick."

That was hardly the only example of the GOP's impulse to place the "dictates of (their) passions" over "the state of facts and evidence." The administration favored "abstinence" programs over contraceptive counseling and resisted attempts to market Plan B, the "morning after" pill. They insisted that if you tell kids sex is bad, and make it riskier, they won't have it! On what planet is that realistic?

Or take the party's position on immigration (which Bush, to his credit, resisted). Send the 12 million illegal immigrants (many of whom have American children) back where they came from! Now there's a triumph of "passions" over "evidence."

Science does not have all the answers. It must always be balanced against moral values and competing priorities. But America is not an ideological country and never has been. That's one reason Obama was elected president. Now he has to keep governing with an understanding that "facts are stubborn things."

Cokie Roberts' latest book is "Ladies of Liberty: The Women Who Shaped Our Nation" (William Morrow, 2008). Steve and Cokie Roberts can be reached at stevecokie@gmail.com.