Congressman Paul Ryan, a hero to conservatives and lightning rod for Democrats, was taking centre stage Wednesday night (local time) at the Republican National Convention, accepting the party's nomination to be Mitt Romney's vice presidential running mate in the campaign to defeat President Barack Obama.
Ryan's nationally televised speech on the second day of the storm-shortened convention will be a debut of sorts for the 42-year-old from the Midwestern state of Wisconsin.
Though a leader on budget policy in Congress, Ryan was not well-known outside Washington when tapped by Romney this month.
The selection of Ryan, author of a plan to reduce the federal deficit, excited Republicans sceptical of Romney's commitment to conservative principles.
Ryan also brought to the ticket youthful energy and a down-to-earth appeal lacking in the stiffer, more aristocratic Romney.
But Democrats pounced on the nomination, saying Romney was now clearly wedded to Ryan's proposals to cut spending by revamping health care programs for the elderly and poor.
Ryan was expected to talk about his Irish immigrant ancestors and small-town values, offering a personal presentation of a lawmaker largely known for sober policy analysis.
In excerpts released ahead of the speech, Ryan lauded Romney, saying the former Massachusetts governor "will not duck the tough issues" if he wins the White House.
"After four years of getting the run-around, America needs a turnaround, and the man for the job is Governor Mitt Romney," he said.
The speech comes at a gathering struggling for attention as Tropical Storm Isaac cast a pall from the nearby northern coast of the Gulf of Mexico. The storm had threatened Florida earlier in the week and prompted Republicans to postpone Monday's start of the convention.
So far, Ryan has not changed the dynamics of the presidential race. Polls continue to show Romney and Obama in a statistical tie ahead of the November vote.
The economy is the biggest issue in the race. While voters have more confidence in Romney on economic matters, they like Obama better on a personal level.
A poll by the Pew Research Centre and The Washington Post found Americans deeply divided about Ryan, whom they described as conservative, intelligent, fake and phony.
Traditionally, vice presidential picks have little effect on US presidential elections, though John McCain's selection of then-Alaska Governor Sarah Palin jolted the race four years ago.
Her electrifying speech was the highlight of the 2008 convention, but her poor performance in subsequent interviews left the widespread impression she was unprepared for the vice presidency.
McCain spoke Wednesday ahead of Ryan. Without mentioning Obama by name, McCain accused the president of failing to lead on defence spending and on grave international issues as well.
"Sadly, for the lonely voices of dissent in Syria and Iran and elsewhere who feel forgotten in their darkness ... our president is not being true to our values," he said.
Also speaking Wednesday was Condoleezza Rice, secretary of state under President George W Bush. Rice's appearance and McCain's comments mark some of the few moments in which international affairs have received attention at the convention, where speakers have repeatedly bashed Obama for his handling of the economy, the growth in the federal deficit and his signature health care program.
Senate Republican leader Mitch McConnell said the country knows what's on the president's iPod, but has no idea what he plans to do about a looming tax hike.
He said Obama seems more interested in earning a spot on the pro golf tour than in solving the nation's problems.
Romney accepts his party's nomination in a nationally televised speech Thursday night, the third and final full day of the convention.
Romney and Ryan were formally nominated in roll call votes Tuesday.
Romney left Tampa briefly to speak Wednesday before a major veterans group, the American Legion. He said Obama "has allowed our leadership to diminish."
"In dealings with other nations, he has given trust where it is not earned, insult where it is not deserved and apology where it's not due," he said.
Opinion polls show Obama getting high marks on national security after ending the war in Iraq, drawing down the conflict in Afghanistan and ordering the killing of terrorist leader Osama bin Laden.
Obama, campaigning before a university crowd in Virginia, declared himself unimpressed with the Republican convention.
"You can listen very carefully, very hard, and you won't hear them offer a clear serious path forward," he said.