It is not totally uncommon for politicians who have left office to run for President years later.
Abraham Lincoln had not been in public office for 12 years, after serving one term in the House of Representatives, when he ran for and won the Presidency in 1860.
Richard Nixon had not been in public office for 8 years, although he ran for California Governor two years after leaving the Vice Presidency in 1960, and won the Presidency in 1968.
Ronald Reagan had not been in public office for 6 years, although he ran unsuccessfully for the Presidential nomination of his party two years after leaving the Governorship, and won the Presidency in 1980.
But now, in 2015, we have a whole slew of candidates out of public office for a long time.
Jeb Bush left the Florida Governorship in 2006, so it will be ten years since he held office.
Rick Santorum lost his Pennsylvania Senate seat in 2006, so it will be ten years since he held office, although he ran for the Presidential nomination of his party in 2012.
Mike Huckabee left the Arkansas Governorship in 2006, so it will be ten years since he held office, although he ran for the Presidential nomination of his party in 2008.
George Pataki left the New York Governorship in 2006, so it will be ten years since he held office.
Jim Gilmore left the Virginia Governorship in 2001, so it will be 15 years since he held office, although he ran briefly for the Presidential nomination of his party in 2008, and lost an attempt at a Senate race in 2008, as well.
Bob Ehrlich left the Maryland Governorship in 2006, so it will be ten years since he held office, although he ran for reelection in 2006 and lost, and tried again for the Governorship in 2010 and lost both times to Martin O’Malley.
This is a record number of candidates who have been out of office for so long, 10-15 years in duration.
Also, three candidates have NEVER held public office–Carly Fiorina, Dr. Benjamin Carson, and Donald Trump.
So NINE potential candidates out of what are now a potential 18-19 in total have long ago left office, or never held office!