DENVER – Democrats opened their national convention on Monday, seeking peace in the family as they pursue victory in the fall for Barack Obama and his historic quest for the White House.

An appearance by the ailing, aging Sen. Edward M. Kennedy of Massachusetts and a primetime speech by Obama’s wife, Michelle, headlined the convention’s first night.

In excerpts released in advance, the would-be first lady said she and her husband were raised with solid American values: “that you work hard for what you want in life, that your word is your bond and you do what you say you’re going to do, that you treat people with dignity and respect, even if you don’t know them, and even if you don’t agree with them.”

The convention’s opening gavel fell with Obama and Hillary Rodham Clinton still struggling to work out the choreography for the formal roll call of the states that will make him – a 47-year-old senator bidding to become the first black president – the party nominee.

“There is no doubt in anyone’s mind that this is Barack Obama’s convention,” the former first lady told reporters. And yet, she said, some of her delegates “feel an obligation to the people who sent them here” and would vote for her.

As the delegates took their seats in the Pepsi Center, Obama campaigned in Iowa, the first in a string of swing states he is visiting en route to Colorado. He arranged to watch his wife’s speech on television later from Kansas City, then speak briefly to the convention via a huge TV screen.

Howard Dean, the party chairman, rapped the opening gavel precisely on schedule at 3 p.m. Mountain Time – before only a smattering of delegates.

“We are ready to compete in all 50 states in November,” he said, even though Obama has already written off large portions of the South and Mountain West.

Schumer and Van Hollen said only a small fraction of Clinton’s delegates remained unreconciled to Obama’s triumph in the bruising primaries of the winter and spring.

Perhaps so, but they were vocal about it, and officials said one of the issues under discussion was whether to permit a noisy floor demonstration by Clinton’s supporters when the former first lady’s name is placed in nomination on Wednesday night.

Kathleen Kennedy Townsend, the eldest child of the late Robert F. Kennedy and a former lieutenant governor of Maryland, said the animosity that some Clinton delegates feel toward Obama is worsening. “There’s a moment that you want to enjoy your bitterness,” she said, although she emphasized that she is supporting Obama.

All the talk about disunity was grating on some.

“To stay wallowing in all of this is not productive,” said House Speaker Nancy Pelosi of California.

“So we can talk about this forever, or we can talk about how we’re going to take our message to the American people, to women all across America, to see the distinctions” between Obama and McCain.

Obama’s campaign set that as one of the goals of the con week.

“Obama’s major challenge at this convention is to focus on the middle class, to show empathy because he had to climb his way up,” to demonstrate he has plans to remedy their concerns and the ability to get things done in Washington, Schumer said.