With Obama, Romney prepping for debate, campaigns rely on candidates' surrogates They may be the country's two most visible political candidates, but President Obama and Mitt Romney now primarily are staying behind closed doors to prepare for their first presidential debate Wednesday night, leaving behind their running mates and other surrogates to keep up the stump speeches, TV appearances and other campaign duties. Both candidates are spending the days leading up to the debate in battleground states. Obama is in Nevada and Romney is in Colorado, but each is spending the bulk of his time preparing for the big night. Obama has been huddling with advisers at a suburban Las Vegas resort and is expected to spend the next couple of days there before heading to Denver for the prime-time TV debate. Obama briefly left the lakeside resort Sunday evening for a rally. "What I'm most concerned about is having a serious discussion about what we need to do to keep the country growing and restore security to hardworking Americans," he said at the rally. That's the debate you deserve. Romney practiced early Monday in Massachusetts -- where he also spent most of the weekend working with his debate team - before heading to Denver for an evening rally. He is expected to resume preparations there until the debate. Meanwhile, Vice President Joe Biden is scheduled to attend two campaign events Tuesday in North Carolina -- in Charlotte, then in Asheville. First lady Michelle Obama will be at a campaign event in Cincinnati, Ohio, then a campaign fundraiser in Seattle. GOP vice presidential nominee Rep. Paul Ryan on Monday evening begins a campaign bus tour in Iowa, and Romney's wife, Ann Romney, will attend a rally in Henderson, Nev. The stakes are high for both candidates, but especially for Romney, who with five weeks until Election Day trails Obama in many of the nine states that are expected to determine the outcome of the White House race. Both camps have downplayed expectations for the first debate. But Romney supporters, political historians and others know a strong performance from him could change the trajectory of the contest. The first of the three debates will focus on domestic issues. But Republicans are keeping up the pressure on Obama on international issues, particularly his administration's handling of the attack on a U.S. consulate in Libya that led to the death of the American ambassador and three others. Over the weekend, while Obama and Romney were off the campaign trail, Ryan appeared on "Fox News Sunday" and shot down the notion that his running mate needed a breakthrough performance Wednesday night. He also said he didn't think one event would make or break the campaign. But New Jersey's Republican Gov. Chris Christie said that after the first debate: "This whole race is going to be turned upside down." Obama senior campaign adviser David Axelrod, meanwhile, appeared on CNN's "State of the Union." On Saturday, Ryan spoke to supporters in New Hampshire, while Biden stumped in Florida. Romney's team has made no secret of the fact its candidate has been practicing for the debates intensely for several weeks. Ohio Republican Sen. Rob Portman, who is playing Obama in practice sessions, travels frequently with Romney. Obama aides have kept quiet about how and when the president is practicing. Some top members of his debate team, including Axelrod and senior White House adviser David Plouffe, traveled with the president to Nevada on Air Force One. Sen. John Kerry, D-Mass., who is standing in for Romney in Obama's practices, made his own way to the resort in Henderson.