Biden Decides Not to Run for PresidentU.S. Vice President Joe Biden has decided not to seek his Democratic Party's nomination for the presidency, ending months of speculation about whether he would run. Speaking at the White House Rose Garden Wednesday, Biden said the grieving process after his son Beau died of brain cancer in May "doesn't respect or much care about things like filing deadlines or debates and primaries and caucuses." "I believe we're out of time, the time necessary to mount a winning campaign for the nomination," Biden said, with his wife, Jill, and President Barack Obama standing next to him. "While I am not going to be a candidate, I will speak out clearly and forcefully as to where we stand as a party and where we need to go as a nation." Biden, 72, also praised President Obama, saying "he led this nation from crisis to recovery." "This party, our nation, will be making a tragic mistake if we walk away or attempt to undo the Obama legacy, he said. Biden, who spent more than three decades in the U.S. Senate, representing Delaware, had previously launched two unsuccessful presidential campaigns, the most recent in 2008. Former Secretary of State Hillary Clinton is the frontrunner for the Democratic Party's nomination for the presidency in 2016, with Vermont Senator Bernie Sanders running second in recent opinion polls.\n\nRepublican frontrunner Donald Trump was quick to react on Twitter. Democrat Sanders also took to Twitter to thank Biden for his public service.  Sam Verma contributed to this report