FILE - In this Thursday, Feb. 2, 2012 file photo, Donald Trump greets Republican presidential candidate, former Massachusetts Gov. Mitt Romney, after announcing his endorsement of Romne

 

              FILE - In this Thursday, Feb. 2, 2012 file photo, Donald Trump greets Republican presidential candidate, former Massachusetts Gov. Mitt Romney, after announcing his endorsement of Romne
FILE - In this Thursday, Feb. 2, 2012 file photo, Donald Trump greets Republican presidential candidate, former Massachusetts Gov. Mitt Romney, after announcing his endorsement of Romney during a news conference in Las Vegas. President Barack Obama and Romney, have visited the state, competing strenuously for Nevada's six electoral votes in what has become one of the most intense swing-state contests. Romney's wife, Ann, is at left. (AP Photo/Julie Jacobson, File)