The South Dakota senator, who was once considered one of the prize show-ponies in the 2012 Republican Candidate's corral, is not running for president this time around:

For months now, my wife Kimberley and I have received encouragement from family, friends, colleagues, and supporters from across South Dakota and the country to run for the presidency of the United States. We have appreciated hearing their concerns about where the country is headed and their hopes for a new this time, I feel that I am best positioned to fight for America’s future here in the trenches of the United States Senate.

President Obama, who appeared eminently take-downable six months ago, is suddenly looking less vulnerable. I expect a lot of this cycle's longshot candidates are taking the extra time to consider whether or not they even want to give it a shot this time around.