U.S. President Barack Obama (C) attends the annual Congressional Baseball Game, pitting Republicans against Democrats for charity, at Nationals Park in Washington June 11, 2015. REUTERS/Jonathan Ernst 

U.S. Senator Rand Paul (R-KY) (C, in red) reacts to striking out during the annual Congressional Baseball Game, pitting Republicans against Democrats for charity, at Nationals Park in Washington June 11, 2015.REUTERS/Jonathan Ernst 

A fan holds a sign reading "Let's Make a Trade," an apparent reference to current trade legislation, as U.S. President Barack Obama attends the annual Congressional Baseball Game at Nationals Park in Washington June 11, 2015. REUTERS/Jonathan Ernst 

U.S. President Barack Obama (2nd L) interacts with fans at the annual Congressional Baseball Game, pitting Republicans against Democrats for charity, at Nationals Park in Washington June 11, 2015. REUTERS/Jonathan Ernst 

U.S. Senator Rand Paul (R-KY) (C, in red) reacts to striking out during the annual Congressional Baseball Game, pitting Republicans against Democrats for charity, at Nationals Park in Washington June 11, 2015. REUTERS/Jonathan Ernst 

U.S. President Barack Obama (2nd L) and U.S. Representative Dan Kildee (D-MI) (L) pump their fists after a good play at the annual Congressional Baseball Game, pitting Republicans against Democrats for charity, at Nationals Park in Washington June 11, 2015. REUTERS/Jonathan Ernst 

U.S. President Barack Obama (L) shakes hands with U.S. Representative Joe Barton (R) (R-TX) as he attends the annual Congressional Baseball Game, pitting Republicans against Democrats for charity, at Nationals Park in Washington June 11, 2015. REUTERS/Jonathan Ernst 

U.S. President Barack Obama (3rd L) attends the annual Congressional Baseball Game, pitting Republicans against Democrats for charity, at Nationals Park in Washington June 11, 2015. REUTERS/Jonathan Ernst 

U.S. President Barack Obama (2nd R) and U.S. Representative Dan Kildee (D-MI) (R) wave to fans at the annual Congressional Baseball Game, pitting Republicans against Democrats for charity, at Nationals Park in Washington June 11, 2015. REUTERS/Jonathan Ernst TPX IMAGES OF THE DAY

U.S. Senator Rand Paul (R-KY) (C, in red) reacts to striking out during the annual Congressional Baseball Game, pitting Republicans against Democrats for charity, at Nationals Park in Washington June 11, 2015. REUTERS/Jonathan Ernst 

U.S. President Barack Obama (C) greets fellow Democrats in their dugout at the annual Congressional Baseball Game, pitting Republicans against Democrats for charity, at Nationals Park in Washington June 11, 2015. REUTERS/Jonathan Ernst 

U.S. President Barack Obama (L) talks with U.S. Representative Dan Kildee (D-MI) (R) as he attends the annual Congressional Baseball Game, pitting Republicans against Democrats for charity, at Nationals Park in Washington June 11, 2015. REUTERS/Jonathan Ernst 

U.S. President Barack Obama waves as he attends the annual Congressional Baseball Game, pitting Republicans against Democrats for charity, at Nationals Park in Washington June 11, 2015. REUTERS/Jonathan Ernst