DENVER — President Barack Obama and his White House rival Mitt Romney hunkered down Tuesday to prepare for the high-stakes televised debate upon which their political futures depend. With the day's public schedules wiped clean and the protagonists behind closed — Obama at a resort in the Nevada desert and the Republican nominee in Denver, Colorado — their running mates filled the campaign void. With barely five weeks to go before the November 6 vote, both Obama and Romney were preparing intensely for perhaps the most high-profile moment of the 2012 campaign: a prime-time, face-to-face debate watched by tens of millions. Each made only brief appearances on Monday night. Romney addressed a rally shortly after arriving in Colorado, while the president delivered freshly baked pizzas to one of his Nevada campaign offices. “Nevada's going to be close. It's going to be close all across the country," said Obama, who hugged volunteers and called others on the phone to talk about honing his debate technique. “It's very nice. Although basically they're keeping me indoors all the time. It's a drag. They're making me do my homework," Obama said. “This is my last campaign so we want to leave it all on the table and work as hard as we can." Romney, a multimillionaire investor and former governor of Massachusetts, on Monday mocked the punditry surrounding the debates and how people want to know “who's going to score the punches." “In my view it's not so much winning and losing (but) an opportunity for each of us to describe the pathway forward for America that we would choose." Former New Hampshire governor John Sununu, a Romney supporter who often plays the role of attack dog on the campaign trail, also dismissed the point-scoring that tends to bubble up during the debates. “I'm not a great believer in zingers, unless they're fact-based," Sununu told Fox News on Tuesday. “I think the key to a debate is to be precise in what you say, precise in your responses, and maintain a tone that the public thinks is not demeaning to the office." With Obama and Romney laying low, their running mates seized the spotlight. Vice President Joe Biden hit the trail in the battleground of North Carolina, where he was to deliver remarks in Charlotte and then Asheville. Romney's running mate Paul Ryan kicked off day two of a bus tour through Iowa, where he outlined the importance of the election. A Washington Post-ABC News poll out Monday gave Obama a slimmer 49 to 47 percent lead, but, tellingly, likely voters in swing states sided with the president by 52 to 41 percent. The stakes are high for both candidates, but the debates may be the last chance for Romney to make a dramatic impression on undecided voters and perhaps melt the narrative that has built up around him as a multimillionaire plutocrat who is out of touch with everyday Americans. Romney has been practicing for the debates for weeks. He has plenty of experience under his belt, having taken the debate stage about 20 times with Republican rivals during the primaries, but a one-on-one face-off with the president is a more intense affair. Ohio Senator Rob Portman, who is playing Obama in practice sessions, is in Colorado with the Republican nominee, while Romney stand-in Senator John Kerry, the Massachusetts Democrat, is in Nevada with Obama. Pennsylvania judge halts ID law A judge Tuesday blocked Pennsylvania from requiring voters to show identification in the election, a decision that could influence turnout in a top electoral prize in the presidential race. Commonwealth Court Judge Robert Simpson issued a partial preliminary injunction that halts the requirement that people show either a state driver's license, government employee ID or a state non-driver ID card in order to vote on Nov. 6. — Agencies