By all accounts, Barack Obama’s father, the Kenyan student studying in America, was cocksure and impressed with his own talents. The arrogance gene must be dominant. Obama clearly has it.

And that, more than any other factor, is driving his summertime swoon. Hubris made him reach for too much, too soon; brazenly overpromise about the effects of his program; overestimate his control of events; think the golden touch of his brilliant team could solve intractable problems; and believe his words could trump reality.

The Obama team is fiddling with his health-care talking points. But the verbiage is beside the point. What Obama needs is a little modesty. It’s easy to imagine an alternative history of a more cautious Obama administration that wouldn’t have stoked a voter backlash in all of six months.

It would have begun with the recognition that he won office sounding like a tax-cutting moderate devoted to paying for “every dime” of his program, against a terrible candidate in the middle of a recession blamed on the incumbent Republican president. Even Howard Dean might have won in these circumstances. Obama’s victory wasn’t as transformative as it appeared. He was given an opening — to address people’s economic anxieties, detoxify the Washington debate and occupy the center.

As a start, he could have taken steps to address the financial crisis — basically continuing the Bush program, as he has — and pursued a genuinely bipartisan stimulus. A smaller stimulus would have split Republicans and given Obama bipartisan cover. The Obama administration wouldn’t have felt compelled to make extravagant claims for it keeping unemployment beneath 8 percent, and it wouldn’t have stoked intense deficit fears.

Obama wouldn’t have begun to take ownership of the economy so quickly, and congressional Republicans would have shared it. As it is, he has lashed himself politically to the unemployment rate, which he has no control over and is typically the last economic indicator to turn around in a recovery.

He could have followed up the stimulus with incremental health reforms — say, new insurance regulation and subsidies for the uninsured — in a continuation of the salami-slice approach to health care that has been so successful for Democrats. Again, he’d have gotten substantial Republican support. At the six-month mark, he’d have a few important, if not sweeping, legislative accomplishments; he’d have avoided all of the liabilities of his stimulus and health-care proposal; and he would have split the Republican Party. He’d own the center.

That’s what might have been. The real, overreaching Obama is sinking of his own weight. On health care, he has neutralized many of the industry groups that rallied against HillaryCare and benefited from positive network news coverage. But pluralities in most polls still oppose his grandiose plan. The more he talks about it, the more the plan and his job-approval rating — down to 52 percent in Gallup — sink.

Obama has single-handedly brought Republicans back on fiscal issues. In the new NBC/Wall Street Journal poll, Republicans now are more trusted than Democrats to deal with taxes, the deficit and spending. Republicans haven’t led on the deficit in that poll for more than a decade. In a Pew poll, approval of Obama’s handling of the economy is down to 38 percent. Just 48 percent now trust him to keep his word, according to the NBC/WSJ poll. That’s a judgment on the disparity between his campaign and his governance, and on his unbelievable claims on behalf of his overly ambitious programs.

People are still fond of Obama and want him to succeed. In the Pew survey, 74 percent say they like him. Independents disapprove of his performance on the economy and the deficit, but are still optimistic about him in the long run. Despite all the excesses of the past six months, they haven’t given up on Obama. He can reconnect with them, and the rest of the public, with some modesty. If he can’t muster it for real, he should at least pretend.

Rich Lowry is a syndicated columnist. He can be reached via e-mail at: comments.lowry@nationalreview.com.