(Reuters) - With less than three weeks left before election day, the youth vote has once more come into focus. A student concerned about his future job prospects asked the first question at the Hofstra University presidential debate Tuesday night, and both candidates have set up extensive campus operations in swing states.

In another clear bid for younger voters, President Barack Obama will appear this evening on Jon Stewart's "Daily Show," the sort of venue challenger Mitt Romney has avoided so far.

Obama defeated Republican John McCain by a roughly two-to-one margin among voters aged 18 to 29 in 2008. The president's lead is large but less commanding this time around. Likely voters in this age group prefer Obama to Romney by 54 percent to 36 percent in Reuters/Ipsos polling from the week ending October 14. http://bit.ly/QY09hI

The Romney campaign is working to mobilize students unhappy with the president's record, with 188 chapters of a pro-Romney student group on campuses in 11 "target states," according to a campaign aide.

"I don't think you'll see the president enjoying the same amount of support that he had in 2008, very simply because the Obama economy has created a lost generation of young voters," the aide said.

He added that the campaign's young groups have made over 2 million "voter contacts," either by "calling them, knocking on the door, having a friend drive them to the polls."

The Obama campaign has gone a step further, bringing buses to some campus rallies that later take students to register or vote early.

For both sides the efforts to register students living on campus have been complicated in some swing states by new voter ID and verification laws. In Florida, for instance, voters who are away from home on election day will not be able to cast out-of-county provisional ballots.

A list provided to Reuters by the Obama campaign names 26 schools the president visited between the end of March and the beginning of October, while Romney aides estimated that the former governor has visited "roughly 50" campuses.

Obama has largely visited community colleges and big state schools, while Romney's most prominent visits have been specially tailored. His major foreign policy address of the fall was at Virginia Military Academy on October 8. When he was looking to establish his credentials with evangelical voters after the primary season in May, he delivered the commencement address at Liberty University in Lynchburg, Virginia.

In Ohio in mid-September, Romney visited the home of the 2011 national intercollegiate dressage champions: Lake Erie College. Romney's wife, Ann, is the owner of a horse that competed in dressage in the 2012 Olympics in London.

The Romney campaign has an uphill climb with the youngest voting demographic. Likely voters overall believe Democrats are better for young Americans than Republicans by a 44 percent to 29 percent margin. For likely voters between 18 and 29 years old, this gap is an overwhelming 53 percent to 19 percent.

Undaunted, the Romney aide said "I don't have a percentage or a volume that's the magic number we're going to win here. Our goal is to go out and talk to every young American."