Republican vice-presidential nominee Paul Ryan vowed Wednesday that he and Mitt Romney will take bold steps that span generations – shrinking federal spending and firing a faltering economy.

During his address, Ryan focused on policy, telling the Republican National Convention that the ticket is poised to tackle tough issues head-on – including revamping big-dollar Medicare and Medicaid programs.

“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.”

The Wisconsin congressman, in office since 1999, is House Budget Committee chairman and has emerged as a fiscal firebrand. He graduated from Miami University in 1992.

Before the convention crowd, Ryan insisted the nation must face fiscal reality. He has championed plans for budget cuts and a revamping of Medicare and Medicaid.

“So here is our pledge,” Ryan said. “We will not duck the tough issues – we will lead. We will not spend four years blaming others – we will take responsibility.”

He also drew one of his largest rounds of applause by echoing the ticket’s commitment to erasing the federal health care overhaul approved by a Democratic-controlled Congress in 2010.

“The president has declared that the debate over government-controlled health care is over,” Ryan said. “That will come as news to the millions of Americans who will elect Mitt Romney, so we can repeal Obamacare.”

Ryan, the first major party nominee born in the 1970s also focused on reaching out to young voters. President Obama won a large majority of 18-29 year old voters in 2008.

“College graduates should not have to live out their 20s in their childhood bedrooms, staring up at fading Obama posters and wondering when they can move out and get going with life,” Ryan said. “Everyone who feels stuck in the Obama economy is right to focus on the here and now. And I hope you understand this too, if you’re feeling left out or passed by: You have not failed, your leaders have failed you.”

Romney’s choice of Ryan as his running mate has helped rally wavering hard-line budget conservatives to the Republican ticket.

Their sizable presence in the party is underscored by the decision from convention organizers to mount two countdown clocks in the Tampa Bay Times Forum, which display the nation’s mounting debt level.

Scott Gilliam, an alternate delegate in the crowd from Butler County, said, “Ryan has brought youthful energy back to the Grand Old Party. His remarks tonight have energized the convention and given the delegates a call to arms to make change happen.”

But while the addition of Ryan bolstered the ticket’s conservative credentials, it also has given Democrats a political target.

A poll last week by Quinnipiac University showed that Medicare remains a top issue for likely voters in the key swing states of Ohio, Florida and Wisconsin, and that more respondents trust President Obama to manage it than Romney.

Six in 10 voters in each state said they want Medicare to continue providing health insurance to older Americans, as it does now. Less than one-third of voters said it should be changed in the future, according to the survey.

Ryan said he and Romney are committed to maintaining benefits for those age 55 and older. Medicare cannot endure for future generations unless retooled, he said.

Romney and Ryan want to change Medicare for younger Americans from the fee-for-service program it is now to one where government provides subsidies for beneficiaries to buy private insurance.

Democrats, though, have blasted the proposal and Wednesday took out a full-page ad in The Tampa Tribune accusing Ryan of trying to “end Medicare as we know it.” Two billboards near the convention site reflect similar themes.

Ryan also helped set the table for Romney, who is poised to accept the presidential nomination tonight.

“Our nominee is sure ready,” Ryan said. “His whole life has prepared him for this moment – to meet serious challenges in a serious way, without excuses and idle words.”