Paul Ryan promised last night that he and Republican presidential contender Mitt Romney would make the tough choices needed to lead a US economic turnaround that generates jobs and cuts government spending and debt.
Mr Ryan accepted his nomination as Mr Romney's running mate at the Republican convention in Tampa, Florida, drawing repeated roars from delegates as he vowed to challenge US president Barack Obama's economic policies and confront Democrats on changes to the popular Medicare health program for seniors.
A fiscal conservative and budget expert, Mr Ryan said the White House race would offer "the clearest possible choice" in the November 6th election about possible remedies for a sluggish economy and high unemployment.
"Before the math and the momentum overwhelm us all, we are going to solve this nation's economic problems," Mr Ryan said in a speech that introduced the little-known Wisconsin congressman to voters.
"We will not duck the tough issues - we will lead. We will not spend four years blaming others - we will take responsibility," he said.
"So here's the question: Without a change in leadership, why would the next four years be any different from the last four years?"
Mr Ryan pointed out his elderly mother, Betty, in the audience when talking about Medicare and drew laughs when he mocked Mr Romney's old-fashioned choices in music.
But the Obama campaign criticised Mr Ryan for misleading voters on Medicare, a deficit reduction plan in Congress and even a factory closure in his hometown of Janesville, Wisconsin.
"If Paul Ryan was Pinocchio his nose would be back in Janesville about now," Mr Obama campaign spokeswoman Jen Psaki said on Twitter.
Mr Romney's selection of Mr Ryan, chairman of the House of Representatives Budget Committee, has energized party conservatives who have doubted Mr Romney at times and has put Mr Ryan's proposed changes to Medicare at the centre of the campaign debate.
Mr Ryan's budget plan would rein in government spending and shift some Medicare participants into private insurance plans purchased with the help of government subsidies, a proposal that Democrats charge would put future benefits for seniors at risk.
On the second full day of the convention, Republicans also criticized Mr Obama's foreign policy and featured a parade of w omen and Hispanic speakers trying to broaden Mr Romney's appeal.
Republicans hope to strike a balance at the convention between sharp indictments of Mr Obama's leadership and a broader introduction of Mr Romney's plans for the economy and the softer side of a candidate who has had trouble connecting with voters.
It seems to be working for Mr Romney so far.
A Reuters/Ipsos online poll yesterday showed him deadlocked with Mr Obama among likely voters at 43 per cent each - an improvement for Mr Romney from Mr Obama's two-point lead on Tuesday and four-point lead on Monday.
Mr Ryan's speech set up Mr Romney's big night tonight, when he accepts the presidential nomination in a major speech.
The former private equity executive must make Americans feel more comfortable with him while laying out a path to economic and an end to high unemployment.
Then the campaign season moves into the two-month final stretch after Democrats meet next week in Charlotte, North Carolina, for their own convention.
The strengths of budget hawk Mr Ryan and ex-businessman Mr Romney are on the economy, but the Republicans also brought out foreign policy heavyweights at the convention.
Condoleezza Rice, who served as secretary of state under former Republican president George W Bush, said Mr Romney and Mr Ryan were ready to lead the United States back to a role of international leadership.
"Mitt Romney and Paul Ryan will rebuild us at home and inspire us to lead abroad. They will provide an answer to the question, "Where does America stand?" she said.
Arizona senator John McCain accused Mr Obama of allowing the decline of US influence.
At an American Legion gathering in Indianapolis, Mr Romney tried to counter Democratic criticism of his inexperience abroad and accused Mr Obama of failing to stand by America's allies.
"In dealings with other nations, he has given trust where it's not earned, insult where it's not deserved and apology where it's not due," he said
Foreign policy and military matters are points of vulnerability for Mr Romney. A trip abroad last month aimed at burnishing his credentials was plagued by gaffes and stumbles.
But US voters are firmly focused on the economy at home.
Mr Ryan promised Republicans they could win the Medicare debate with Democrats.
"Medicare is a promise, and we will honour it. A Romney-Ryan administration will protect and strengthen Medicare, for my mom's generation, for my generation, and for my kids and yours," he said to cheers.
"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," he said.
Republican delegate Ronda Vuillemont-Smith of Oklahoma said the selection of Mr Ryan would help focus the ticket on spending cuts and reducing the size of government.
"I honestly feel that Ryan brought backbone to the ticket," she said.
Reuters