VP hopefuls center stage as US race tightens AFP 10/11/2012 10:57:01 AM The US vice presidential debate, while often a knock-around affair, is rarely considered likely to mark a turning point in a White House race. Nevertheless, this year's battle promises fireworks.Thursday night's duel brings the Democrats' veteran populist bruiser Vice President Joe Biden head to head with Congressman Paul Ryan, a youthful fiscal policy wonk who is a hero to the conservative Republican right.The clash of generations, styles and ideologies comes just as President Barack Obama has seen his national poll lead evaporate following a terrible debate showing against his newly confident challenger Mitt Romney.A hands-down victory for Ryan could set the seal on this apparent Republican comeback as the race enters the closing straight. A punchy Biden performance could halt Obama's slide before he loses his lock on key swing states.But both camps face a minefield too.Ryan's policy expertise may not go over well to everyday voters in the debate arena, and he will come under sustained attack for drafting a budget proposal that would have seen billions slashed from popular programs.Biden is a more stirring speaker, but has a reputation for memorable gaffes and excesses. If he sees himself as the White Knight charging to the rescue of Obama's beleaguered campaign, he may overreach in spectacular fashion.At 69, Biden is probably on his last national campaign, and will be keen to stop 42-year-old Ryan -- an industrialist's son and Washington insider competing in his first televised debate -- in his tracks.Ryan strains to emphasize his everyman credentials as a hunter, father and devout Catholic -- but can't compete with the easy-going charm of Biden, with whom many voters say they could imagine having a beer.But Biden's informal style can let the Pennsylvania native down when his tongue runs away with him.In August, he was accused of "playing the race card" when he told a mixed-race audience in the former slave state of Virginia that Romney's plan to relax banking regulations would put Americans "back in chains."And he provided Romney with a free punchline just before last week's top of the ticket debate, when he declared the American middle class had been "buried" during recent economic woes -- much of it during Obama's first term.Ryan is much more tightly buttoned, as befits a Washington insider who was elected to Congress aged only 28 and has been returned six times since by his constituency.His hunky sportman's frame and baby-blue eyes proved popular among some women voters, judging by a flurry of Internet responses to his nomination, but his social conservatism and plans to cut healthcare proved a tougher sell.So, just as in 2008 when Biden faced former Alaska governor and conservative media darling Sarah Palin, the older man finds himself tasked with countering a young but inexperienced champion of the right.Last time around, Biden was cautious not to appear overbearing or insulting in his encounter with a provocative Palin, and came out the winner.Whatever happens, the two main White House challengers will still have a chance to get their campaigns back in order. After Thursday's vice-presidential bout, Obama and Romney face each other twice more on October 16 and 22.