The biggest mistake President Obama could make now is to overinterpret the election results.

One of the dumbest things politicians do in the aftermath of elections is to claim a mandate. Even dumber is when they actually believe it. And reelected presidents are especially susceptible to the mandate delusion.

At a news conference just after his reelection in 1996, Bill Clinton pointed to this pitfall. Noting he had just read a book about presidential second terms, Clinton observed that “sometimes the president thinks he has more of a mandate than he does and tries to do too much in the absence of cooperation.”

George W. Bush, after his re-election in 2004, succumbed to this very trap. “When you win, there is a feeling that the people have spoken and embraced your point of view. And that’s what I intend to tell the Congress,” Bush crowed. “I earned capital in the campaign, political capital, and now I intend to spend it.”

As it turned out, Bush’s capital was illusory. His press for private Social Security accounts went nowhere.

To some extent, Obama has more claim to a mandate on taxes than Bush did on Social Security. Bush mentioned Social Security during the campaign, but it was not the centerpiece of his bid for a second term.

For Obama, the question of taxes — in particular, the argument that the wealthiest Americans should be asked to pay more — was, as the president said Friday, “a central question during the election . . . debated over and over again.”

Nonetheless, to acknowledge that Obama has more of a claim to a mandate is not to say he has a solid hold on one. And the president and his allies are busy proclaiming the certainty of a mandate.

Vice President Biden: “On the tax issue there was . . . a clear sort of mandate about people coming much closer to our view about how to deal with tax policy.”

Senate Majority Leader Harry Reid: “The mandate was . . . everybody agrees that the richest of the rich have to help a little bit.”

Reelection architect David Plouffe: “Voters clearly chose the president’s view of making sure the wealthiest Americans are asked to do a little more in terms of reducing the deficit.”

And the president himself: “On Tuesday night we found out that the majority of Americans agree with my approach.”

Deep breath, folks. The president’s argument is correct: The wealthiest can and should pay more. The assertions of national consensus are premature.

First, look beneath the president’s impressive electoral college numbers. America remains a closely divided country. Flip about 155,000 votes in just four states — Ohio, Florida, Virginia and New Hampshire — and you end up planning a Romney inaugural. The freakish closeness of Florida 2000 obscures the minuscule percentage of the vote that those switches would entail: little more than one-tenth of 1 percent of the national vote.

Looked at another way, three of the last four presidential elections have featured a difference of fewer than 3 percentage points in the popular vote. Not since the 1880s has the country had a string of such close races.

A further caution: It’s dangerous to confuse electoral victory with policy endorsement. Voters cast their ballots for an array of reasons — they didn’t think that Romney understood the problems of people like them; they perceived that the economy was improving and gave Obama credit for it; they were reassured by Obama’s response to Hurricane Sandy; they hated Romney’s car elevator.

True, exit polls showed 63 percent of voters saying that taxes shouldn’t be raised to help reduce the budget deficit; in answer to a separate question, 47 percent said that taxes should go up only on the wealthy, and 13 percent said that they should be increased for all.

But there is a difference between being able to point to support for your policy and arguing that the election settles the question. It didn’t — any more than, as House Speaker John Boehner claimed, the reelection of a Republican House majority demonstrated there is “no mandate for raising tax rates.”

A politician who runs without an agenda cannot claim any mandate on election night. Yet even for a politician who runs with one, the hard work of convincing begins anew the next day.