DENVER -- Democratic officials wasted no time casting John McCain as the next incarnation of the Bush presidency Monday, going on offense as the Democratic National Convention got underway in Denver.

A rapid-fire slate of speakers kicked off festivities in the Mile High City, leading up to Michelle Obama's headlining speech at the end of the night.

The convention was expected to be more aggressive than the relatively passive 2004 convention, and the front-end speakers used their brief remarks to both praise Barack Obama as an agent of change, and criticize McCain as a continuation of the Bush administration.

“Republicans say that John McCain has experience. We say that John McCain has the experience of being wrong," said House Speaker Nancy Pelosi, pointing to his support of "failed" Bush policies.

Pelosi led the audience in a refrain of "Barack Obama is right and John McCain is wrong," as delegates started to fill up the arena.

Several Democratic congressmen hit the same themes.

"America cannot afford a third Bush-Cheney term, which is what a McCain presidency would be," Texas Rep. Silvestre Reyes said.

"Anyone who's been a friend of Bush 90 percent of the time isn't a friend of America's families," said California Rep. Grace Napolitano, referring to McCain's voting record in the Senate.

"Our families cannot afford four more years of stagnation, recession and failure," New York Rep. Jose Serrano said.

Even former Republican Rep. Jim Leach, of Iowa, censured his own party during a late-night address on the convention floor.

Charging that his party had “broken with its conservative heritage,” he enthusiastically endorsed Obama for president, calling him a "transcending candidate."

The speakers described their presumptive nominee as a champion of the working class.

In between remarks, videos played of Obama on the campaign trail and of supporters, including Michelle Obama, offering their testimony on his character and potential.

Illinois State Sen. Emil Jones Jr., whom Obama considers a political mentor, gave the audience a snapshot of his early days on the South Side of Chicago.

"America, this is a unique man," he said. "Barack Obama, the next president of the United States, will deliver change this country truly, truly needs."

Meanwhile, Republicans have set up shop about a mile down the road from the Pepsi Center, where the convention is being held, to rebut charges from the Democrats. One of their main attacks is to claim that disenchanted Hillary Clinton supporters are contributing to a divided party.

Pelosi praised Clinton on the convention floor Monday.

“All Democrats salute Hillary Clinton for her excellent campaign. Our party and our country has been strengthened by her candidacy,” she said.

Former President Jimmy Carter, along with his wife Rosalynn, also walked briefly on stage and waved after a video played featuring his work in New Orleans.

The video interspersed clips of New Orleans residents with Carter speaking to the camera. The former president chided the Bush administration for the aftermath of Hurricane Katrina.

“The federal government practically ignored their plight,” he said in the video. “I don’t have any doubt that when we have a Democrat back in the White House this January, Barack Obama, this will never happen again.”

Carter did not address the convention audience.

FOXNews.com's Judson Berger contributed to this report.