Besides Romney and his coterie of angry white talk show hosts, it's George W. Bush.
Romneytron mimicked Bush at every turn. He ran as a CEO, appealing to the same stubborn acolytes. He criticized McCain for criticizing Bush. He preached to the choir.
And while conservatives nationwide opted for The Anchorman -- by a slim margin -- Republicans as a whole chose the anti-Bush candidate (notwithstanding some regrettable pandering by McCain).