ST. PAUL, Minn. — Third-party candidates Gary Johnson and Virgil Goode are blips in the presidential race. They have little money, aren't on stage for presidential debates and barely register in the polls — when survey takers even bother to list them as options.

Yet in a tight race between Democratic President Barack Obama and Republican challenger Mitt Romney that likely will be won or lost at the margins, even blips can be a big deal.

Obama's campaign has quietly been tracking the two former Republican officeholders who could be pivotal in key states. Romney's campaign insists it's not worried, even though Republican allies have failed to keep them off state ballots.