1. George W. Bush
More than anyone else Bush is responsible for decimating the ranks of qualified Republicans who could take on Obama. A successful Presidency can produce a new crop of future Presidential candidates for the party that controls the White House. The vice president and cabinet officials, as well as governors and senators elected over the course of the administration, are historically major sources for a party’s next round of candidates. The Bush years had the opposite effect. It was unthinkable that his vice president would run for higher office and much of his cabinet left Washington tainted by the President’s unpopularity. Moreover, Bush helped sink his party in the 2006 and 2008 elections, thus depleting the ranks of potential Republican candidates for 2012.
The Republican Party rebounded in 2010, but it will take longer than two years for many Presidential-caliber candidates to emerge after the wreckage of the late Bush years.