"The present administration has made its choices. And Mitt Romney and I have made ours: Before the math and the momentum overwhelm us all, we are going to solve this nation's economic problems. And I'm going to level with you: We don't have that much time. But if we are serious, and smart, and we lead, we can do this," he said.
Conservative Republicans who were lackluster in their support of Romney have embraced his running mate. Crowd size at events with Ryan in tow has dwarfed those at which Romney appears alone.
"He has an amazing ability to energize a crowd, while presenting the important facts so that people can reach a common sense conclusion about the changes needed in this country," Republican strategist Alice Stewart told ABC News.
Ryan wrote tonight's speech with help from some of the GOP'S best speechwriters. Matthew Scully, who wrote Sarah Palin's convention speech and was also George W. Bush's speechwriter, andl John McConnell, Dick Cheney's speechwriter, contributed to the address.
Before Ryan spoke, former Secretary of State Condoleezza Rice took the stage. Rice is the only senior member of the previous two Republican administrations to attend the convention.
Both former president George W. Bush and his father George H.W. Bush appeared in video tributes along with their wives, but were not in attendance. After reminiscing about their administrations and complimenting each other, the two former presidents said they were supporting Mitt Romney's bid for the White House.
"He's a good man," the elder Bush said.
Former Arkansas Gov. Mike Huckabee also addressed the convention earlier in the evening. Huckabee, a former evangelical minister, appealed to evangelical Christians, an important party bloc wary of Romney's Mormon faith.
"I care far less as to where Mitt Romney takes his family to church than I do about where he takes this country," he said.
Huckabee's comments come after Ann Romney also mentioned her husband's faith while addressing the convention on Tuesday, indicating a shift in the campaign's previous approach of avoiding direct references to Mormonism.