WASHINGTON -- Top Democratic officials, hoping to unify their party as a long, bruising primary season came to a close, last night reached an agreement that would seat the Michigan and Florida delegations at the party's summer convention in Denver and give Sen. Barack Obama of Illinois an almost insurmountable lead in the race for the Democratic presidential nomination.

One adviser to Sen. Hillary Rodham Clinton suggested that the former first lady would fight the decision, which gives her a net gain of only 24 delegates.

Following a tense day of testimony and debate at a hotel in Washington, the 30 members of the Democratic Party's Rules and Bylaws Committee decided to give the Florida and Michigan delegates a half-vote each.

The same committee last year stripped all delegates from the two states when they broke party rules and scheduled January primary contests.

Yesterday's decision on Florida -- which gave Mrs. Clinton 52.5 pledged delegates and 33.5 delegates to Obama -- was unanimous.

But eight members voted against the plan for Michigan, where Mr. Obama wasn't on the Jan. 15 ballot and nearly 40 percent of voters selected "uncommitted." To compensate, the rules committee awarded 34.5 delegates to Mrs. Clinton and 29.5 to Mr. Obama.

Harold Ickes, a committee member and Clinton adviser, was irate.

"I am stunned that we have the gall and the chutzpah to substitute our judgment for 600,000 voters," he said, warning that Mrs. Clinton could take her objections before the Convention Credentials Committee.

Such a move might lead to a floor fight at the convention in Denver. Some party officials yesterday seemed eager to avoid that scenario.

"Harold, I respect and love you," said Donald Fowler, a Clinton supporter and former Democratic National Committee chairman. "But this is what I think we should do."

As the committee votes took place, furious Clinton backers in the audience shouted "Denver!" and "Madame President!"

"The world is not perfect, but it is good. And when you can come here and you can leave with unity it's what this party needs," Alice Huffman, a committee member from California who has endorsed Mrs. Clinton, told the crowd.

"You just took away votes!" someone shouted at her.

Any compromise was likely to disappoint Mrs. Clinton, who needed a major boost to upset Mr. Obama's chances of winning. With the additional delegates from Michigan and Florida, the number needed to secure the nomination is now 2,118.

That leaves Mr. Obama 66 delegates short, according to the Associated Press.

The final primaries are today, when Puerto Rico, with 55 delegates at stake, votes, and Tuesday, when Montana (16 delegates) and South Dakota (15 delegates) vote.

"I want this to be a healing process," Jon M. Ausman, a Democratic National Committee member from Tallahassee, Fla., told the committee when he presented the half-delegate plan. "So when we leave this room we're all wearing the same blue jerseys so we can go after the Republicans in their red jerseys in November."

Mr. Ausman, a longtime Florida political operative, gave a heavily technical but impassioned plea to members, arguing that some punishment for the state is appropriate, but the party's rules require at least half of the delegates from his state to be seated at the August convention in Denver.

The committee, he said, went too far in stripping all delegates from the two states because Democratic Party rules use the word "shall," not "may," to describe the seating of delegations. In other words, some delegates from both states have to go to Denver.

Mr. Ausman is remaining neutral in the Obama-Clinton battle. The Obama campaign backed his proposal.

"In life you don't get everything that you want, but I want it all," Florida State Sen. Arthenia L. Joyner, speaking on behalf of the Clinton campaign, said. "I'm asking for a full vote."

Rep. Robert Wexler, D-Fla., said the Obama campaign was making an "extraordinary" concession by agreeing to an approach that would net Mrs. Clinton 19 delegates from the state.

The Michigan case was far more complicated.

The state's Democratic leaders, including Sen. Carl Levin, called for a rough delegate split based both on the election results and exit polls that showed a significant number of Obama supporters had gone to the polls, despite his absence from the ballot.

"As you have all pointed out it is imperfect. There is no scientific way to reach the conclusion that we reached, but here is a fair way," Mr. Levin told the committee. "It is a path forward that has produced unity in Michigan."

Former Rep. David Bonior of Michigan, who was representing the Obama campaign, called for an even split.

Former Michigan Gov. James Blanchard said the Obama campaign erred by removing the candidate's name from the ballot even though it wasn't required.

That led to a sharp retort from Donna Brazile, a committee member who hasn't publicly endorsed any candidate: "My momma always told me to play by the rules and to respect those rules."

Clinton and Obama supporters booed and hissed and cheered and yelled at dozens of points during the nearly five hours of morning presentations.

Outside, hundreds of protesters gathered in front of the Marriott Wardman Park Hotel, where the committee was meeting. There were several busloads of angry Florida Democrats who still have bad memories from the state's 2000 election fiasco.

Many, although not all, were Clinton backers.

"Florida voted and it was a legal election," said Linda Spencer, 61, a party activist from Fernandina Beach, Fla., who voted for former Sen. John Edwards of North Carolina in her state's primary election. "The votes need to be counted."

She wore a glittering red, white and blue cap and a T-shirt bearing the name of a newly formed group: floridademandsrepresentation.org.

The protesters -- who chanted "50 states, not 48" -- came from all over the U.S., not just Michigan and Florida.

"I'm getting madder by the day at the DNC," said Martie Lee, 62, of Corry, Erie County. "It's the principle."

A Clinton supporter and lifelong Democrat, she said she was "incensed" about what she called sexist treatment of the former first lady during the campaign. She said she would vote for Sen. John McCain, the presumptive GOP nominee, in the fall if Mr. Obama wins the Democratic nomination.

"There's such anger among women," she said.

In the morning, representatives from both states tried to deflect blame for bringing the primary process to this point. Sen. Bill Nelson, D-Fla., faulted his state's GOP-controlled legislature for pushing the Jan. 29 primary date into law last year.

And Mr. Levin said Michigan's move was a reaction to decades of dominance by New Hampshire and Iowa in the early stages of the primary process.

"No state should have the right to go first and second every election," he said.

At one point, Mr. Ickes implied that Mr. Obama had his name removed from the Michigan ballot to "curry favor" with participants in Iowa's first-in-the nation caucuses on Jan. 3, which he won.

Allan Katz, a committee member from Florida who was wearing an Obama pin during the hearings, said no one should compare the current dispute with Florida's 2000 recount mess.

"That election was stolen," he said, citing a common refrain among state Democrats who believe former Vice President Al Gore defeated then Texas Gov. George W. Bush.