By Edward Epstein, CQ Staff

To the 84,000 cheering fans who savored his acceptance speech in the home of the NFL’s Denver Broncos, Barack Obama scored a spectacular touchdown Thursday evening.

But those fans — delegates to the Democratic National Convention and supporters from across Colorado and neighboring states — are already pumped up over Obama’s presidential bid.

The true impact of his 43-minute speech will become clear in coming days as polls show how much of a bounce he and running mate Joseph R. Biden Jr. get in national polls and in surveys of the 18 states the campaign is targeting as battlegrounds in the race against Republican John McCain .

“The big uncertainty was whether he could meet the high expectations set by his 2004 speech,” said Darrell West, an expert on political communication at the Brookings Institution in Washington, D.C. “But with a crowd cheering every paragraph, it is clear that he roused the faithful and excited people all across America. He delivered an inspiring speech that got his general election campaign off to a great start.”

In the speech, Obama lambasted McCain and President Bush, even while calling for a toning down of partisanship in Washington.

To the seasoned politicians and the rank-and-file in the packed stands at Invesco Field, Obama’s words and the entire experience of a five-hour outdoor convention session packed with speeches, flag waving and music from such stars as Sheryl Crow, Stevie Wonder and John Legend added up to a powerful experience.

Hillary Rodham Clinton , whom Obama bested for the nomination after a lengthy contest, pronounced the speech “excellent.”

“It was exciting to be here tonight,” the New York senator said.

“So this is real tonight. This is not politics,” said Sen. John Kerry , D-Mass., his party’s losing 2004 presidential nominee. “I think people will leave here with a wonderful sense of direction.

“Nothing like this has been seen in modern times of the party and I think it’s a moment for change,” he added.

There had been some grumbling in Denver this week that the Democrats weren’t being tough enough on McCain. But Rep. Robert Wexler of Florida said Obama handled that.

“ Barack Obama took out the sharp knives tonight and Democrats are fighting back. This speech shows Barack Obama ’s got a backbone,” said Wexler, an early Obama supporter.

Rep. Tom Allen of Maine, who is hoping Obama’s coattails can help him win a Senate seat this fall, said, “He proved tonight he is tough enough to run for president. He created the vision [of where] he wanted the country to go and how he wanted to take it.”