Why did GOP invite Clint Eastwood?

The beloved actor/director, 82, was the "mystery guest" at the Republican Convention, a warm-up act for Sen. Mario Rubio of Florida, who introduced candidate Romney. He strode out on the stage, hair uncombed and a little wild, with his familiar, stiff-legged authority, and proceeded to deliver an improvised piece of performance art that triggered unintentional amusement and confusion within the Tampa Bay Times Forum and throughout the viewing audience.