On NBC's "Meet the Press": David Axelrod, senior adviser to the Obama campaign, Sen. Rob Portman (R-OH), Sen. Rubio.
CNN's "State of the Union": Reps. Cathy McMorris Rodgers (R-WA) and Donna Edwards (D-MD); Newt Gingrich; former Gov. Bill Richardson (D-NM), Sen. Mark Warner (D-VA), former Rep. Tom Davis (R-VA).
On ABC's "This Week": Sen. Marco Rubio (R-FL), Chicago Mayor Rahm Emanuel.
On CBS' "Face the Nation": Stephanie Cutter, deputy campaign manager for the Obama campaign, Kevin Madden, adviser to the Romney campaign, Sen. Rubio.
On "Fox News Sunday": Sens. Lindsey Graham (R-SC) and Dick Durbin (D-IL).