DES MOINES, Sept. 29 — Resurfacing before a partisan crowd, former Vice President Al Gore declared tonight that "George W. Bush is my commander in chief" and implored Democrats and Republicans alike to offer Mr. Bush their unwavering support.

Members of the Iowa Democratic Party, gathered here for their annual Jefferson-Jackson Day Dinner, leapt to their feet when Mr. Gore said the message he had heard from Iowans as he toured the state in the last two days was that people must unite.

"That's what I've been hearing in Iowa," Mr. Gore said in a speech that was restrained, and often conversational. "We are united behind our president, George W. Bush, behind the effort to seek justice, not revenge, to make sure this will never, ever happen again. And to make sure we have the strongest unity in America that we have ever had.

"That's what I'm hearing in Iowa. I hear it in every community I have visited. There are no divisions in this country where our response to the war on terrorism is concerned."

Mr. Gore's speech, in his first major political appearance since he lost the White House, was decidedly different from the one his advisers said he had planned to deliver when he accepted the state party's invitation last August. He had been expected to raise questions about the leadership of the man who defeated him last year after one of the closest presidential elections in history, setting the stage for a possible run again for president in 2004.

But tonight, Mr. Gore rejected partisanship and called for a continuation of the bipartisanship that has marked Washington since Sept. 11.

"This country is more united than at any time I can remember in my life," he said. "We come together tonight not as partisans but as patriots. We come together not only first and foremost, but solely as Americans at a time our county has been attacked."

While he said "our president will have to make some decisions that we'll question in the days ahead," Mr. Gore said it was vital that "this burst of bipartisanship we're seeing can't be temporary." Recalling his eight years in the White House, he said, "I can tell you that in the best of times and the best of circumstances there are tough judgment calls."

Mr. Gore, who has been teaching and writing a book, did not even hint about his own political plans. But he told supporters at small fund-raising events before the dinner that he had made no decisions about running again.

The former vice president, who defeated former Senator Bill Bradley in the caucuses here and won Iowa in the general election, also took the opportunity to thank his backers here.

Though this is the biggest political event of the year for the Iowa Democratic Party, organizers sought to make the tone subdued and relatively nonpolitical. The tables and the hall at the Polk County Convention Complex here were smothered in American flags. After a rendition of "The Star-Spangled Banner," a huge flag was unfurled from the ceiling, prompting cheers from the audience.

There were tables outside the hall pitching local candidates, but most of the 1,600 attendees refrained from wearing political buttons. If anything, they fastened small flags on their lapels or blouses.

Gov. Tom Vilsack said in his speech that while the nation must unite to fight terrorists, it could not neglect issues like education and battling poverty.

He drew a standing ovation with this close: "God bless Democrats, God bless Republicans. God bless independents. God bless Americans — all."

Lt. Gov. Sally J. Pederson told the crowd, "On Sept. 11, we all became patriots."

But she also drew applause when she went on to say, "While we support our president, we did not all become Republicans."

Mr. Gore arrived in Burlington, Iowa, on Thursday night and set out, alone, in a rented brown Ford Taurus.

In a stark contrast to the days when he would wend around the state in a long vice-presidential motorcade, he improvised on this trip. Map in hand, he drove from town to town, surprising old supporters by calling them on a cellphone and then meeting them for coffee, meals or just to chat. (He joked tonight that he got lost more than once.) He spent Friday night at a Holiday Inn Express in Cedar Rapids. This morning, he rose early and brought doughnuts to striking machinists in Amana.

Democratic officials said they had briefly weighed whether to postpone the event but decided to go on with it — in the spirit of Mr. Bush's exhortation that life must go on.

While his speech was mostly sober, Mr. Gore opened with some quips about his new life and about his relationship with his wife, Tipper, who accompanied him here. But he said it was difficult even joking given the crisis the country was enduring, and the audience responded enthusiastically to their standard bearer of last year.