Paul Ryan, on the cusp of accepting his party's vice presidential nomination, says it's time to meet the country's challenges "without excuses and idle words."

"After four years of getting the run-around, America needs a turnaround," Ryan said in prepared remarks, "and the man for the job is Governor Mitt Romney."

In excerpts of his major convention address, the Wisconsin congressman touted Romney as a serious man for serious times -- particularly when it comes to the budget problems he's devoted his career to addressing.

"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," Ryan said. "But if we are serious, and smart, and we lead, we can do this."

Ryan pledged they would not "duck the tough issues," but "lead."

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The address, set for late Wednesday night, follows on the heels of New Jersey Gov. Chris Christie's keynote in which he said the GOP ticket is prepared to deliver "hard truths" to the country. Ann Romney also pledged that her husband "will not fail."

Ryan's speech would sustain the drumbeat of unified confidence in Tampa in the ability of the party's nominee to get the job done -- in Ryan's case, that means closing the deficit and bringing down the debt by tackling entitlements, other spending and tax reform.

The Wisconsin congressman has been quietly preparing his speech for days.

Ryan, chairman of the House Budget Committee, is best known for his controversial plans to overhaul Medicare and the tax system. They are likely the kinds of "hard truths" Christie raised Tuesday night, as the New Jersey governor claimed Romney and Ryan would lead a "new era of truth-telling" in Washington.

Ryan will also accept the Republican vice presidential nomination Wednesday night, all while setting the stage for Romney's address on the closing day.

Democrats, though, were hard at work casting Ryan as a regressive choice for the country. A new video released Wednesday by the Obama campaign cast him as "out of step" with voters, and someone from a "bygone era."

The video criticizes Ryan for being the architect of an "extreme" budget that would overhaul Medicare and for seeking to defund Planned Parenthood.

Ryan spokesman Brendan Buck said the video was a "tired and misleading" attack by Obama "in an attempt to divert attention away from his failed record."

Obama, meanwhile, is traveling Wednesday to Charlottesville, Va., the last stop on his two-day trip to counter the GOP convention message and to appeal to younger voters in college towns.

Both parties were pushing forward with their political plans while closely monitoring Hurricane Isaac, which arrived in Louisiana late Tuesday. Republicans had largely canceled the first day of their convention as Isaac appeared bound for Tampa. White House officials said they were monitoring the storm but, as of early Wednesday, had no plans to adjust the president's travel plans.

The GOP convention's opening day was raucous, with a string of fiery speeches -- and one deeply personal address from Ann Romney.

Christie was as tough on Obama as he was supportive of Mitt Romney, ratcheting up the convention tone. Christie claimed "doubt and fear" have seized a country that four years ago put its stock in hope and change.

Christie said Romney will "tell us the truth" and "lead with conviction" and that, in the end, the country will thrive "in a second American century."

"If you're willing to hear the truth ... about the hard road ahead, and the rewards for America that truth will bear, I'm here to begin with you this new era of truth-telling," Christie said.

Warming up the crowd for Ryan Wednesday is another high-profile roster of Republican names. The list includes former Secretary of State Condoleezza Rice, Kentucky Sen. Rand Paul and 2008 presidential nominee John McCain.

The Associated Press contributed to this report.