Supporters of Barack Obama found the inspiration they were seeking in the Democratic nominee's prime-time speech last night but many Republicans said it only compounded their concerns about him.

Phyllis Ring, 81, of Fort Collins, Colorado, watched the speech from her wheelchair in the end zone of Denver's Invesco football stadium. She said she found the speech "very, very inspirational," adding: "It definitely lived up to my expectations."

She was joined at the mass rally by her friend Alice Buchholz, also 81, of Barrington, Illinois. "I thought it was marvelous. He laid out what he is going to do. It's not going to be easy but he is going to try."

The speech gave Obama an opportunity to state the case for why he should be elected over Republican John McCain in November to succeed President George W. Bush.

Obama, who would be the first black American president, delivered a hard-hitting address vowing to renew his vision of the American Dream.

"Individual responsibility and mutual responsibility. That's the essence of America's promise," he said.

Obama spoke to two audiences -- the one in the stadium, which was filled with passionate, flag-waving supporters as well as curious onlookers -- and millions more who tuned in to watch on television.

CELEBRITY?

"Call him a celebrity? Call him an elitist?" said Betsy Hyder, who watched the speech with her children at home in Davis, California. "I see him as very Midwestern, pragmatic yet generous."

Susan French, a Democrat who watched the speech in Cincinnati, Ohio, said she was impressed by how forceful Obama was, though she thought the speech could still leave him open to attack.

"He did a great job addressing the areas where he has been attacked: patriotism, his qualifications for the job and how he plans to pay for all his ideas," she said.

"The over-the-top stadium show (surrounding the speech) might help motivate his supporters but it might be playing into the hands of his critics who try to paint him as a rock star with no substance," she said.

But to many Republicans, the speech merely amplified many of their concerns about the candidate who, at 47, would be one of America's youngest presidents if elected on Nov. 4.

"He described a chance to keep the American promise and he made a lot of promises. He is the pied piper of promises," said Mike Vanderboegh, of Pinson, Alabama.

"A government that is powerful enough to give you everything you want can take everything you have," he said, adding, "He is scarier than (former President Bill) Clinton because he is arrogant and a true believer."

'FEEL-GOOD SPEECH'

Bob Lindsey, a business owner in Birmingham, Alabama, picked up on a frequent criticism of Obama -- that little lies behind the candidate's capacity to spin fine words.

"It was a feel-good speech. It made you think about yourself and where you wanted the United States to go. It was just him making you feel good for the purpose of him getting elected," Lindsey said.

Obama put himself on the map when he delivered the keynote address at the Democratic convention in 2004 and his capacity to inspire Democrats with soaring oratory has proved fundamental to his appeal since he launched his bid for the nomination in February 2007.

But soaring oratory has brought its own pressures and one of his challenges was to win over independent voters.

Matthew Steffey, a professor at Mississippi College, said the speech's success was to tap into the economic discontent of voters. "There was great resonance with his criticism of the Bush administration and McCain's support for it," he said.