Paul Ryan energized Mitt Romney's White House bid Wednesday with a scathing take-down of Barack Obama's economic record as he accepted the vice presidential nomination at the Republican convention.
Adding youthful vim and policy vigor to the Romney ticket, the 42-year-old rising star from small-town Wisconsin received a standing ovation for his impassioned pitch to American voters 10 weeks from election day.
"I accept the duty to help lead our nation out of a jobs crisis and back to prosperity. And I know we can do this," Ryan said, exhibiting little sign of nerves during his 35-minute speech, by far the biggest of his political life.
Ryan accused Obama of saddling the US economy with four years of failed big government policies and held up Romney, a 65-year-old former Massachusetts governor, as the man to turn things around with his business acumen.
"After four years of getting the run-around, America needs a turnaround, and the man for the job is Governor Mitt Romney," he said.
Romney will formally take up the nomination with his all-important acceptance speech to the convention in Tampa, Florida on Thursday, the climax of three days of rousing addresses by party grandees and rising stars.
He lies neck-and-neck with Obama in national polls ahead of a November 6 election that should be the challenger's for the taking, given the sour economy and stubbornly high unemployment.
Romney's vice presidential pick was seen as crucial four years after John McCain electrified conservatives by choosing inexperienced Alaska governor Sarah Palin, only to see her wither in the national spotlight.
Democrats have portrayed Ryan as an extreme, budget-cutting friend of the rich who would gut beloved social programs.
But Republicans have used the selection of the seven-term congressman, whose budget plan is the party's blueprint to fix the flagging US economy, to breathe fresh life into a race that had been in danger of drifting away from Romney.
Ryan took his chance in the convention spotlight to assail the president's record, saying Obama's promises of hope and change had fallen flat after four years of fiscal recklessness, ballooning debt and joblessness.
"It all started off with stirring speeches, Greek columns, the thrill of something new," he 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."
His address, carried live on cable TV across America at prime time, contained a clear pitch to working class and middle class Americans who may find it hard to identify with Romney's background of wealth and privilege.
Analysts agreed that Ryan gave a strong speech, but the burden is now on Romney to use his own address on Thursday to energize voters and close the still-yawning likability gap with Obama.
The Obama campaign had upped the pressure on Ryan in the hours leading up to the speech, releasing a new web video accusing him of favoring outdated top-down economics, tax cuts for the wealthy and the replacement of the popular Medicare program for the elderly with a voucher system.
Speeches earlier on Wednesday by Senator John McCain and former secretary of state Condoleezza Rice focused on foreign policy -- which has taken a back seat to the economy in the campaign -- saying Romney would restore US leadership in the world and accusing Obama of letting down Israel and other allies.
Romney was meanwhile preparing for his own address on Thursday, when he will formally accept the nomination and make his own case to a prime-time audience in perhaps the most important speech of his political career.
He took to the stage briefly on Tuesday's storm-delayed opening night of the convention to give his wife Ann a kiss after her well-received speech, which sought to humanize a candidate often seen as stiff and awkward.
She delivered her side of the bargain, blending a targeted pitch to vital women voters with a personal narrative about Mitt that dwelt largely on their all-American love story, their wholesome family and his winning attitude.
"This man will not fail," Ann Romney said. "This man will not let us down. This man will lift up America!"