Call it the Obama paradox: He’s been a failure as a president, but he looks headed for reelection, anyway.

Sure, things could change between now and November if there’s a stock-market plunge, a scandal, an Iranian nuclear test, or a truly game-changing moment in one of the presidential debates. It’s possible the polls showing Mr. Obama leading Mitt Romney both nationwide and in battleground states are all inaccurate, or that a final tidal wave of television commercials by the Romney campaign and its allies will be able to change the dynamic of the campaign, the same way Mr. Romney recovered after surges by Newt Gingrich and Rick Santorum in the primaries.

But if Mr. Obama is reelected, how can it possibly be explained?

The answer is somewhere in these three plausible story lines:

The voters are re-electing Obama-Boehner, not Obama-Biden. The President Obama who’s leading in the polls isn’t the overreaching president of the first two years of his term, the Obama of the stimulus bill, the Dodd-Frank financial “reform” bill, and ObamaCare. That President Obama disappeared, or at least was hidden away, on Election Day 2010, to be replaced for the most part by the President Obama who worked with the Republican Speaker of the House, John Boehner, to extend the Bush income tax cuts for two years, add a payroll tax cut, keep Guantanamo open, and ratify free trade agreements with Panama, Colombia, and South Korea. The stock market, as measured by the Standard and Poor’s 500 Index, is up about 20% since Election Day 2010. Health care costs and energy costs are leveling off.

By re-electing a Republican House, voters are rejecting President Obama’s argument that things would be better without the Republican obstructionists. They’re saying, instead, that they like the obstructed Obama better than the unobstructed one, and that the combination of a Republican House and President Obama might be something better than a failure.

A second story line is that Romney is a terrible candidate.

This is partly personal, partly policy. Mr. Romney served one four-year term as governor of Massachusetts. He never won the popular ratification that comes with re-election or even with having a hand-picked successor win re-election. His public-sector achievements are so thin that, at the Republican National Convention, he was reduced to trotting out Olympic medalists in the sports of women’s skeet shooting and women’s skeleton to testify to his work on the 2002 Winter Olympics. John Kennedy swam three miles in shark-infested waters towing an injured shipmate; John McCain survived five and a half years of torture in North Vietnamese prisons; Mitt Romney saved short-course speed skating in Salt Lake City.

Mr. Romney is gaffe-prone: “I like being able to fire people”; “I’m not concerned about the very poor.”

Mr. Romney’s most significant public achievements — the Massachusetts health care law that expanded insurance coverage through a mandate and the John and Abigail Adams scholarships to state colleges and universities in the Bay State — don’t contrast well against either ObamaCare or President Obama’s Pell Grant expansion. Voters looking for a candidate to expand health coverage and college access with taxpayer money figure they might as well stick with Mr. Obama.

Mr. Romney did not mention his tax-cutting plans in his convention speech, avoided tax simplification as an issue, and was vague about his plan to reduce tax breaks for upper-income taxpayers (another issue on which he agrees with President Obama.) He ran promising to spend more on Medicare than President Obama would, and praising McCain-Feingold-style campaign spending limits.

Generationally, Mr. Romney, 65-years-old and gray-at-the-temples, is an odd choice to deliver a message about federal debt reduction. Younger Republicans, like Marco Rubio and Paul Ryan, connect better with the younger voters who will have to pay off the debt, and those next-generation politicians may have their chance to do so in the 2016 Republican presidential primary campaign.

Mr. Romney’s economic message was so gloomy that he sometimes sounded like a candidate trying to get elected entirely with the votes of the 8% of Americans who are unemployed.

By this line of explanation, the rejection of Mr. Romney is not so much a rejection of the Republican Party or of conservative or free-market policies or ideas, but of Mr. Romney and his particularly odd campaign.

The third possible explanation is one I hope is not true, but that lurks as a fear in the minds of many of those dismayed by the polls. That is that the “takers” have started to outnumber, and outvote, the “makers.” Add together the 46.7 million Americans on food stamps, the 8.7 million Americans receiving Pell Grants, the 7.6 million unionized government employees, and weigh them against the top 5% of income earners, the roughly 7 million taxpayers making more than about $154,000 a year, who earn about 32% of the adjusted gross income and pay about 59% of the nation’s individual income taxes. We have all kinds of systems and laws in America for protecting the rights of unpopular minorities, but no one has quite figured out how to prevent an election from devolving into “four wolves and a lamb voting on what to have for lunch.”

Margaret Thatcher said socialists “always run out of other people’s money.” Charles Prince, then head of Citigroup, said in 2007, “as long as the music is playing, you’ve got to get up and dance. We’re still dancing.” A worst-case scenario is that the 2012 election will be remembered as one in which voters thought the music was still playing and danced away, only to discover before long that the other people’s money had run out.

Mr. Stoll is editor of FutureOfCapitalism.com and author of “Samuel Adams: A Life.”