During Romney's appearance, the candidate played a word association game with his potential vice presidential nominees, dubbing New Jersey Gov. Chris Christie: “indomitable," Florida Sen. Marco RubioMarco Antonio RubioColbert: Students taking action on gun violence 'give me hope' Lawmakers feel pressure on guns Florida lawmaker's aide fired after claiming shooting survivors were 'actors' MORE “the American dream," real estate mogul Donald TrumpDonald John TrumpAccuser says Trump should be afraid of the truth Woman behind pro-Trump Facebook page denies being influenced by Russians Shulkin says he has White House approval to root out 'subversion' at VA MORE “huge" and his eventual pick, Rep. Paul RyanPaul Davis RyanRepublicans are avoiding gun talks as election looms The Hill's 12:30 Report Flake to try to force vote on DACA stopgap plan MORE (R-Wis.), "creative."

But, Romney quipped at the time, he would choose "David Letterman, to help us both out."