TAMPA, Fla.- Movie icon Clint Eastwood fired up a Republican crowd not used to the attention of Hollywood's A-listers, telling them President Obama had failed in his chance to get America on the right track.

"We own this country. ... Politicians are employees of ours," said Eastwood, his trademark gravelly voice shaky, but his words embraced by an enthusiastic crowd. "When somebody does not do the job, you've got to let them go."

As perhaps GOP nominee Mitt Romney's most beloved celebrity backer, Eastwood's presence was hoped by convention planners to energize the crowd as it waited to hear from Romney. He had been touted as a mystery guest, although his appearance was a badly kept secret.

The 82-year-old actor's delivery occasionally seemed labored, but he scored repeatedly with jabs at the Democratic tandem now in the White House.

"I never thought it was a good idea for attorneys to be president," Eastwood said while speaking to an empty chair that was supposed to represent President Obama. "I think it's time for maybe a businessman -- a stellar businessman. When someone doesn't do the job, you got to let them go."

Eastwood struck a more serious tone when not speaking to the empty chair, hearkening back to his own emotions when Obama won election four years ago.

"I just thought 'this is great'; everybody was crying, Oprah was crying, I was even crying," the gruff actor-turned-director said, drawing a contrast with the current political atmosphere. "I think now it may be time for somebody else to come along and solve the problem."

In recent days, covention-goers were abuzz about a so-called mystery guest who would help bring the festivities here to a close. But rather than Sarah Palin, Donald Trump or Nancy Reagan, as some speculated, it was the Man with No Name who brought the audience to its feet after a series of speeches that were more about humanizing Romney than exciting Republicans.

He took aim at Obama's policies, mocking his plans to hold trials for terrorist suspects in New York City and close Guantanamo Bay. But he saved arguably his sharpest zinger for Vice Joe Biden.

"Of course we all know Biden is the intellect of the Democratic Party," he said of the gaffe-prone vice president.

Eastwood is not the typical conservative surrogate for Romney. The actor of "Dirty Harry" fame has described himself as libertarian-leaning rather than a Republican -- and he supports abortion rights and gay marriage.

He was featured in a prominent Super Bowl ad about the turnaround of auto manufacturer Chrysler, which some viewed as a subtle endorsement of Obama. When the Academy Award-winner endorsed Romney recently in Idaho, though, such speculation came crashing down.

Still, Tinseltown is hardly fertile ground for Romney -- or the GOP. While Obama has hosted swanky fundraisers with the likes of George Clooney, Steven Spielberg and Anne Hathaway, Romney has settled for endorsements from Jon Voight, Chuck Norris and reality television personality Donald Trump.

But on Thursday it was Romney basking in the spotlight of a celebrity endorsement. And Eastwood couldn't resist closing his remarks with his most famous line.

"I'll start it, you finish it," he instructed the audience. "Go ahead," he said, at which point the crowd roared, "Make my day!"