Joe Biden Opts Out Of Presidential Race

Vice President Joe Biden is decided to forgo a 2016 presidential bid, sources close to Biden tell CBS News.

The decision ends months of speculation about whether Biden would step up to challenge Hillary Clinton, the current front runner for the Democratic nomination and his former Obama administration colleague.

The vice president took his time to consider whether he and his family had the "emotional energy" to endure another campaign, following the tragic death over the summer of his 46-year-old son Beau. While his fellow Democrats gave him his space, pressure mounted for Biden to come to a decision as Democratic voters, party operatives and deep-pocketed donors considered which candidate to line up behind.

Biden was also running up against logistical deadlines: The first filing deadline for appearing on a 2016 primary ballot is November 6 in Alabama. Additionally, the Democratic primary debates are already underway; CBS News hosts the next Democratic debate on November 14 in Iowa.

While Clinton has dominated the race for the Democratic nomination, there's clearly at least some thirst among Democrats for an alternative. Bernie Sanders, the socialist senator from Vermont, has drawn huge crowds to his campaign events, and he has stayed competitive with Clinton in polls in key states, as well as in terms of fundraising.

All the while, Biden had maintained a base of support. Polls throughout the year showed that Biden consistently won the support of at least 10 percent of Democrats nationally and in early-nominating states.

Biden's decision is good news for Clinton, though she hardly has a lock on the nomination. As her Democratic opponents work to keep her on her feet, Clinton will also have to fend off attacks from Republicans scrutinizing her use of a private email account and server, as well as her actions ahead of the September 12, 2012 Benghazi attack.