TAMPA, Fla. —Paul Ryan on Wednesday portrayed himself as the vanguard of a new generation, a potential vice president unafraid to urge politically risky steps to reshape the government and ease America's economic pain.

“I accept the calling of my generation to give our children the America that was given to us, with opportunity for the young and security for the old _ and I know that we are ready,” the 42-year-old Wisconsin congressman said in remarks prepared for prime-time delivery Wednesday at the Republican National Convention.

“We will not duck the tough issues — we will lead. We will not spend four years blaming others — we will take responsibility. We will not try to replace our founding principles, we will reapply our founding principles,” he said, according to transcript.

In accepting the nomination as Mitt Romney's running mate, Ryan — more than any major convention speaker — had the potential to electrify the party's conservative base. He's this year's conservative hero, and his address was designed not only to introduce the seven-term lawmaker to the American public, but also to energize delegates.

“The Ryan pick has helped bring in conservatives,” said Justin Machacek, a faith-based film producer in Fort Worth, Texas, and a convention delegate.

Wayne King, vice chairman of the North Carolina Republican Party, found “Ryan brings an element of enthusiasm Mitt Romney's campaign was missing.”

Ryan got specific. He discussed his controversial budget blueprint, calling it “a plan for a stronger middle class.”

He insisted the 2010 federal health care law be scrapped.

“Obamacare comes to more than 2,000 pages of rules, mandates, taxes, fees and fines that have no place in a free country,” he said in his prepared remarks. “The president has declared that the debate over government-controlled health care is over. That will come as news to the millions of Americans who will elect Mitt Romney so we can repeal Obamacare.”

Ryan's speech was planned as the final message of a night devoted to the theme of “We Can Change It.” Before Ryan, though, the evening's premier events recalled the party's past.

Former Secretary of State Condoleezza Rice, a key adviser on the Iraq and Afghanistan wars, and Sen. John McCain of Arizona, the party's 2008 presidential nominee, were featured speakers.

Delegates also watched a video recalling the presidencies of George H.W. Bush and George W. Bush. Both are skipping the convention. The elder Bush is in failing health. The younger Bush's presidency remains a subject Republicans would rather not discuss. Delegates rarely invoked the younger Bush's name on the convention floor. One reason: a debt clocks loom over the convention hall showing the growing national debt, some of which was accumulated on Bush's watch.

The shadow of that past is a big reason Ryan's speech grew crucial. The House Budget Committee chairman, first elected in 1998, is the author of a detailed plan for reducing future deficits. The most controversial aspect involves revamping how seniors get health care coverage after 2023.

Those turning 65 that year could choose private plans or traditional Medicare, with federal financial support to help pay premiums. Democrats have seized on the idea as a heartless scheme that will ravage seniors' finances. Republican delegates insist something must be done to save a Medicare program bleeding dollars, and they appreciate Ryan's willingness to confront the issue.

“My parents are in their 70s; they know they'll be taken care of. Younger people feel Medicare won't be there for them anyway, and they're going to have to have some sort of long-term care insurance,” said Michael Noftsger, a delegate and banker from Somerset, Ky.

Some delegates loyal to Rep. Ron Paul of Texas remained unenthusiastic about the ticket. Their candidate did not address the convention but was instead featured in a video. His son Rand, a Kentucky senator, addressed the delegates Wednesday.

Of those backing Romney, many delegates, particularly those in Northeast and Pacific Coast states, worried that Ryan might appear as too doctrinaire to undecided voters in the general election campaign.

They added, though, also argued that voters will choose a candidate based on economic issues and little else.

“The issues New England faces are the same issues everyone faces. At the end of the day, the key issue is what you can afford,” said former Rhode Island Gov. Don Carcieri.

He echoed the thoughts of many Republicans — that Ryan's boyish charm will help him overcome the notion that he's too ideologically driven.

“Paul Ryan will help send the right message,” Carcieri said. “He's really personable.”

President Barack Obama was in Charlottesville, Va., on Wednesday, campaigning for a final time before Romney goes before a national audience at the Republican convention Thursday.

He told a mostly college-age crowd not to let the negativity of the campaigns turn them off.

“There are some folks getting sick of politics, sometimes campaigns seem meaner and smaller,” he said, adding that Republicans will tell them, “You were naive last time when you had all that hope and change stuff.”

“What they're hoping, even if you don't vote for them ... they do hope you get so discouraged that you just stay home,” he said. “That's what they're banking on.”