Paul Ryan rallied the Republican convention audience Wednesday night as he formally accepted his party's nomination for vice president and made an urgent plea for the country to get to work turning around its economy and finances.

"We don't have much time," Ryan said, but claimed: "We can do this."

Teeing up the stage for Mitt Romney's nomination speech Thursday night, Ryan repeatedly accused Democrats of falling down on the job. The acerbic speech accused the president of leaving his legions of voters with little more than a record of squandered opportunities and broken promises as they stare at "fading Obama posters" and look for work.

“It all started off with stirring speeches, Greek columns, the thrill of something new,” Ryan said. “Now all that’s left is a presidency adrift, surviving on slogans that already seem tired, grasping at a moment that has already passed, like a ship trying to sail on yesterday’s wind.”

From start to finish, the speech was an unceasing assault on Obama’s record. By the end, he drew thunderous cheers and applause from the convention crowd. And as he has in the past, Ryan tried to draw a sharp contrast throughout.

Obama’s term, he said, has been “a dull, adventureless journey from one entitlement to the next, a government-planned life, a country where everything is free but us.”

Ryan pledged a new direction: "We will not duck the tough issues, we will lead."

He vowed to rein in the size of government, and called on the party to take the journey with them.

“Before the math and the momentum overwhelm us all, we are going to solve this nation’s economic problems,” Ryan said. “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.”

Of the Democrats, he said, “Their moment came and went.”

Ryan catalogued a litany of grievances against the president, from the stimulus and accompanying funding for companies like Solyndra -- “with their gold-plated connections … and make-believe markets” -- to the health care overhaul.

His inner numbers-guy emerged as he tried to explain the disconnect between the economic crisis when Obama took office and Obama’s actions in those first couple years.

“Here we were, faced with a massive job crisis – so deep that if everyone out of work stood in single file, that unemployment line would stretch the length of the entire American continent,” Ryan said. “You would think that any president, whatever his party, would make job creation, and nothing else, his first order of economic business.”

He went on: “Instead, we got a long, divisive, all-or-nothing attempt to put the federal government in charge of health care.”

Ryan also renewed the ticket’s pledge to repeal “ObamaCare” and continued to claim that he and Romney invite a debate about Medicare -- which Democrats have tried to use against Ryan because of his own controversial plan.

But Ryan repeated the argument that the federal health care overhaul is the real danger for Medicare seniors because of the cuts it makes.

“The greatest threat to Medicare is ObamaCare, and we’re going to stop it,” he said. “So our opponents can consider themselves on notice. In this election, on this issue, the usual posturing on the left isn’t going to work.”

Ryan brought the crowd to its feet when he took the stage and again when he left it.

"After four years of getting the run-around, America needs a turnaround," Ryan said at the top, "and the man for the job is Gov. Mitt Romney."

Ryan’s speech sets the stage for Mitt Romney’s nomination acceptance speech Thursday, which will close out the party’s convention and be the GOP’s last word before Democrats convene in Charlotte, N.C., for their nomination gala.

New Jersey Gov. Chris Christie fired up the crowd on the opening night, which was delayed by a day over Tropical Storm Isaac, but Christie left it to Ryan to get into the particulars of what a Romney-Ryan ticket would pledge to achieve for America.

Those particulars have proved controversial.

Ryan, the House Budget Committee chairman, is the author of a Medicare plan that has been a punching bag for Democrats for years now, but even more so since he was tapped as Romney’s running mate. Democrats continued to hammer Ryan on the morning of the speech, releasing a Web video that cast him as a regressive choice from a “bygone era.”

Ryan, though, known for his strict fitness regimen and hobbies ranging from bow-hunting to heavy metal, has brought a vitality to the ticket and has challenged efforts to caricature him as a one-dimensional soak-the-poor conservative.

His selection as GOP running mate was hailed by many conservatives as a serious choice for serious times -- which is how Ryan sought to cast the Romney-Ryan ticket Wednesday night going into the November election.

Jazzed-up delegates pouring into the halls after the speech told FoxNews.com they liked what they heard.

“I think he hit a home run,” said Gerry Geer, a 74-year-old Navy veteran and alternate delegate from Pennsylvania. “He brought up things that nobody has so far this week, like Solyndra. I’m pretty sure Paul Ryan is the one.”

Randy Pullen, an Arizona delegate and former state party chairman, called the speech “fabulous.”

“He said it the way it was: four years of failure -- blame, blame, blame. … He also vowed to cut spending to put us back on track, back to where we were 10 years ago,” Pullen said.

FoxNews.com’s Judson Berger and Joseph Weber contributed to this report.