Obama would be the first major presidential candidate to drop out of the modern campaign financing system for the general election since its creation in 1976 in the post-Watergate era.

CNN: McCain attacks Obama for opting out of public financing

John Edwards, the former senator from North Carolina and 2004 vice-presidential nominee, was the most recent candidate to drop out of the race, having failed to score a win in any of the early contests.

NPR: Solid Wins for McCain; Clinton, Obama Close

There were those who hailed the announcement by initial leadership candidate Simon Thomas to drop out and throw his weight behind her as a gamechanger that would stop Leanne Wood's momentum in its tracks.

BBC: How Leanne left others trailing

He's Klein's campaign manager, who butts heads with Bash and Jared Franklin (Breckin Meyer) over the candidate's decision to drop out of the race.

CNN: 'American Pie' star coming to 'Franklin & Bash'

Though a drop off in turnout among young voters is predictable when there's no presidential candidate on the ticket, there are other reasons the Obama team has to worry about a lower turnout.

CNN: STORY HIGHLIGHTS

Presidential candidate Phil Gramm (R-Texas) will not let the tax cut issue drop, if nothing alse as a political wedge against Senator Dole.

CNN: From Charles Bierbauer

But another moderate candidate in the race, ex-GOP state chair Mike Hellon, refused to drop out of the contest, and Graf benefited from a split opposition.

NPR: A Super Tuesday for Lincoln Chafee

Jesse Benton, Mr Paul's national campaign chairman, said his candidate's second-place finish in New Hampshire meant the rest of the candidates should drop out and support the Texas congressman, in an attempt to block Mr Romney from gaining the nomination.

BBC: Romney heads to South Carolina after New Hampshire win