The era of bipartisanship is over, at least until November.

President Obama's allies have occasionally been irritated that he won't do away with all his bipartisan talk and treat his opponents as they deserve to be treated. These allies/critics must be happy with his speech today in Iowa City, the same place he unveiled his health care proposal in December 2007 and where today he mocked his opponents with the thoroughgoing enjoyment he displayed during the campaign. "Leaders of the Republican Party, they called the passage of this bill 'Armageddon.' " Obama told the audience, to laughter. " 'End of freedom as we know it.' So after I signed the bill, I looked around to see if there [were] any asteroids falling or some cracks opening up in the Earth. It turned out it was a nice day. Birds were chirping. Folks were strolling down the Mall. People still have their doctors."

I half expected Obama to pull out a version of the campaign line he used to flash when he was feeling particularly loose. "Don't be hoodwinked," he used to say of McCain's or Hillary Clinton's claims. "Don't be bamboozled, don't fall for the okey-doke."

Since taking office, Obama has dashed between two postures. When he has made overtly partisan shots, he has pretty quickly returned to his posture as the post-partisan bridge builder. He traveled to Massachusetts in mid-January to beat up on Scott Brown on the eve of the special Senate election, for example, but weeks later, in the State of the Union, he said he would "not give up on changing the tone of our politics." Now, in the last week leading up to the health care vote and in the days since the bill's passage, Obama has stopped bothering with the bipartisanship. He's been forceful, relaxed, and just the kind of fellow Democrats hope can save their fortunes in November.

Conservatives might find this celebration after health care passage unseemly. They might think it's unbecoming of a president of all the people. But Ronald Reagan was even better than Obama at tweaking his opponents like this. This is a fine presidential tradition—even down to the detail of daring your opponents to run on repealing your reforms, as Obama did Thursday and Reagan did in 1982 (though, of course, Reagan didn't make such a big deal about ending partisanship).

Still, the president is smart enough to know that making fun of your opponents by treating them like imbeciles will energize them. There's nothing like an end-zone dance to fire up the other team. But either he's having too much fun or he knows that his side needs to celebrate a little. And he probably also realizes that, given the state of bipartisanship these days, there's not much to lose.

More evidence of the president's decision to drop the bipartisan pretense comes from two speeches he gave about health care reform—one in September to a joint session of Congress and one last weekend to House Democrats.

In September, appealing to lawmakers' sense of compassion, Obama said:

That large-heartedness—that concern and regard for the plight of others—is not a partisan feeling. It's not a Republican or a Democratic feeling. It, too, is part of the American character—our ability to stand in other people's shoes; a recognition that we are all in this together, and when fortune turns against one of us, others are there to lend a helping hand; a belief that in this country, hard work and responsibility should be rewarded by some measure of security and fair play; and an acknowledgment that sometimes government has to step in to help deliver on that promise.

A day before the House vote, though, when Republicans were resolute in their opposition, this kindheartedness is no longer a bipartisan emotion. It is one available only to Democrats:

Something inspired you to get involved [in politics], and something inspired you to be a Democrat instead of running as a Republican. Because somewhere deep in your heart you said to yourself, I believe in an America in which we don't just look out for ourselves, that we don't just tell people you're on your own, that we are proud of our individualism, we are proud of our liberty, but we also have a sense of neighborliness and a sense of community and we are willing to look out for one another and help people who are vulnerable and help people who are down on their luck.