So this is what party unity sounds like. Alice Huffman, a member of the Democratic party's rules and bylaws committee, which met on Saturday to decide the fates of the Florida and Michigan delegations, was explaining herself. She had just sought to allow all of Florida's delegates to vote at the Democratic convention in August, despite the disputed scheduling of the state's presidential primary. But that motion failed, and she was explaining to her 29 fellow committee members and the rest of us in a Washington hotel ballroom why she was now - in the interest of party unity - going to support a second motion that would seat the delegation at half strength.

A woman in the audience yelled: "You just took away votes!" Huffman: "We gave you some back, too. We will leave here more united than we came."

The room, or that portion of it dedicated to Hillary Clinton's advancement to the White House, burst into mocking laughter. She tried to keep talking.

A man yelled: "Lipstick on a pig!"

Huffman countered: "Please conduct yourselves like proper men and women."

At a later point, committee member Everett Ward was trying to speak. A woman in the audience yelled, apropos of what I'm not sure: "What about Iowa? New Hampshire? South Carolina?" Another woman countered: "Shut up!"

At the end of the evening, the committee member Don Fowler leaned into his microphone to thank the co-chairs, James Roosevelt Jr and Alexis Herman. The Clinton supporters in the room, to put it mildly, did not share Fowler's gratitude and made their disapproval known. But hey, Florida and Michigan are settled. The primaries held in defiance of party rules now count, or half-count. The bottom lines are these.

First: Clinton netted a gain of 24 delegates, 19 out of Florida and five out of Michigan. She was hoping for more than twice that.

Second: as for the "magic number"- the number of delegates needed to clinch the nomination - forget the figure 2,026, which did not count the two states. The new magic number is 2,118 (or, according to some people, 2,117).

Third: Obama picked up 63 delegates in Saturday's scrum. He now has 2,053 delegates and is 65 short of sewing up the nomination. Clinton gained 87 delegates. She has 1,877, and is 241 delegates short. (This is pending the tally from yesterday's Puerto Rico vote - she was expected to win there and pick up another 10 or 12.)

And fourth: the number of outstanding delegates is 291, meaning that Clinton would have to persuade more than 80% to throw their lot in with her.

The above numbers confirm what we've known, really, since mid-February. Barack Obama is going to be the Democratic standard bearer. Certainly since the Tuesday night he won Wisconsin (February 19), and arguably since the Tuesday before that, when he rolled up big wins in Maryland and Virginia, it's been all but inevitable.

So what have we been doing these past three-and-a-half months? On the plus side, we've been watching a very useful and necessary toughening of the nominee. Everything that's happened since Wisconsin - the emergence of Jeremiah Wright, the flap over the "bitter" white working class, and so on - has constituted Obama's trial by fire. Far better that he had to answer all those questions in March than in October, with millions more voters paying closer attention.

But at the same time, we've been hostage to the Clintons' inability to come to grips with the fact that Hillary was going to lose. Her final descent into rancid demagoguery about Florida and Michigan, comparing them to Zimbabwe and likening the "cause" of seating the states at full strength to the civil rights movement was, for some observers, the last straw. It was a rules dispute over two states that broke the rules; no one was jailed or lynched, and if anyone disenfranchised the voters of those two states, it wasn't the Democratic party or Obama, it was the political leaders of the states themselves.

We have no idea whether the fuming Clinton partisans at Saturday's meeting represent thousands or millions. But however many of them exist, the fact is that Clinton worked them into this lather - Eve Fairbanks of the New Republic filed a stomach-turning report for her magazine's website on some of the things said about Obama outside the hall - and Clinton is responsible as things move forward for working them out of it. That means, for starters, ending her quest soon and letting her backers know that she's not fighting on to the Denver convention.

But an even greater responsibility falls on Obama as the nominee. Losers have to be gracious, but winners have to be magnanimous. He has a little trouble with magnanimous. He also has few women in his campaign's higher brain trust. He needs to show that he takes the frustrations of Clinton's supporters seriously. And since it seems highly unlikely that he'll offer her the vice-presidency, he'll have to find creative and interesting ways to reach out to Clinton voters.

Remember unity, one America, we're all our brothers' and sisters' keepers - the fundamental premise of the Obama campaign to begin with? Now would be an excellent time for him to put those principles into action.

· Michael Tomasky is the editor of Guardian America michael.tomasky@theguardian.com