President Barack Obama In Colorado On April 24, 2012

President Barack Obama arrives at Buckley Air Force Base on April 24, 2012. (credit: BRENDAN SMIALOWSKI/AFP/Getty Images)

President Barack Obama In Colorado On April 24, 2012

President Barack Obama speaks at the University of Colorado Boulder on April 24, 2012. (credit: BRENDAN SMIALOWSKI/AFP/Getty Images)

President Barack Obama In Colorado On April 24, 2012

President Barack Obama shakes hands while leaving after speaking at the University of Colorado Boulder on April 24, 2012. (credit: BRENDAN SMIALOWSKI/AFP/Getty Images)

President Barack Obama In Colorado On April 24, 2012

President Barack Obama speaks at the University of Colorado Boulder on April 24, 2012. (credit: CBS)

President Barack Obama In Colorado On April 24, 2012

President Barack Obama speaks at the University of Colorado Boulder on April 24, 2012. (credit: BRENDAN SMIALOWSKI/AFP/Getty Images)

President Barack Obama In Colorado On April 24, 2012

President Barack Obama speaks at the University of Colorado Boulder on April 24, 2012. (credit: BRENDAN SMIALOWSKI/AFP/Getty Images)

President Barack Obama In Colorado On April 24, 2012

President Barack Obama arrives to speak at the University of Colorado Boulder on April 24, 2012. (credit: BRENDAN SMIALOWSKI/AFP/Getty Images)

President Barack Obama In Colorado On April 24, 2012

President Barack Obama speaks at the University of Colorado Boulder on April 24, 2012. (credit: BRENDAN SMIALOWSKI/AFP/Getty Images)

President Barack Obama In Colorado On April 24, 2012

People listen as US President Barack Obama speaks at the University of Colorado Boulder April 24, 2012 in Boulder. (credit: BRENDAN SMIALOWSKI/AFP/Getty Images)

President Barack Obama In Colorado On April 24, 2012

President Barack Obama speaks at the University of Colorado Boulder on April 24, 2012. (credit: BRENDAN SMIALOWSKI/AFP/Getty Images)

President Barack Obama In Colorado On April 24, 2012

President Barack Obama speaks at the University of Colorado Boulder on April 24, 2012. (credit: BRENDAN SMIALOWSKI/AFP/Getty Images)

President Barack Obama In Colorado On April 24, 2012

President Barack Obama greets patrons at The Sink on April 24, 2012, in Boulder. (credit: BRENDAN SMIALOWSKI/AFP/Getty Images)

President Barack Obama Departs From Colorado On April 25, 2012

President Barack Obama arrives at Buckley Air Force Base on April 25, 2012. (credit: CBS)

President Barack Obama In Colorado On April 24, 2012

President Barack Obama wipes yogurt off his pants after it was spilled on him by a spectator outside The Sink restaurant April 24, 2012 in Boulder. (credit: BRENDAN SMIALOWSKI/AFP/Getty Images)

President Barack Obama In Colorado On April 24, 2012

President Barack Obama (R) stands with staff and Secret Service after yogurt was spilled on him by a spectator outside The Sink restaurant April 24, 2012 in Boulder. (credit: BRENDAN SMIALOWSKI/AFP/Getty Images)

President Barack Obama In Colorado On April 24, 2012

President Barack Obama with a student outside The Sink on April 24, 2012, in Boulder. (credit: BRENDAN SMIALOWSKI/AFP/Getty Images)

President Barack Obama In Colorado On April 24, 2012

President Barack Obama greets patrons at The Sink on April 24, 2012, in Boulder. (credit: BRENDAN SMIALOWSKI/AFP/Getty Images)

President Barack Obama In Colorado On April 24, 2012

President Barack Obama greets patrons at The Sink on April 24, 2012, in Boulder. (credit: BRENDAN SMIALOWSKI/AFP/Getty Images)

President Barack Obama Departs From Colorado On April 25, 2012

President Barack Obama leaves Buckley Air Force Base on April 25, 2012. (credit: CBS)

President Barack Obama In Colorado On April 24, 2012

President Barack Obama greets patrons at The Sink on April 24, 2012, in Boulder. (credit: BRENDAN SMIALOWSKI/AFP/Getty Images)

President Barack Obama In Colorado On April 24, 2012

President Barack Obama greets patrons at The Sink on April 24, 2012, in Boulder. (credit: BRENDAN SMIALOWSKI/AFP/Getty Images)

President Barack Obama In Colorado On April 24, 2012

President Barack Obama greets patrons at The Sink on April 24, 2012, in Boulder. (credit: BRENDAN SMIALOWSKI/AFP/Getty Images)

President Barack Obama In Colorado On April 24, 2012

President Barack Obama cleans yogurt from his pants after being spilled by a spectator outside The Sink restaurant April 24, 2012, in Boulder. (credit: BRENDAN SMIALOWSKI/AFP/Getty Images)

President Barack Obama In Colorado On April 24, 2012

A rainbow is seen above Colorado countryside from Air Force One April 24, 2012 in Colorado. (credit: BRENDAN SMIALOWSKI/AFP/Getty Images)

President Barack Obama In Colorado On April 24, 2012

A rainbow is seen above Colorado countryside from Air Force One April 24, 2012 in Colorado. (credit: BRENDAN SMIALOWSKI/AFP/Getty Images)