US vice-president Joe Biden has ruled out a third presidential bid, saying that the opportunity to mount a realistic campaign had passed.
The decision strengthens the hand of Democratic frontrunner Hillary Clinton in her bid to win the party's nomination for the 2016 presidential election.
Ending months of speculation about whether he would enter the Democratic race, Mr Biden said the grieving process that he and his family have been going through since the death of his eldest son Beau in May had “closed the window” on a presidential run.
“Unfortunately, I believe we’re out of time, the time necessary to mount a winning campaign for the nomination,” he said.
Speaking in the White House rose garden, flanked by his wife Jill and president Barack Obama, he said that he would not stand quietly on the sidelines of the 2016 campaign.
“While I will not be a candidate, I will not be silent. I intend to speak out clearly and forcefully, to influence as much as I can, where we stand as a party and where we need to go as a nation,” he said.
Mr Biden had been exploring a presidential bid for several months and was said to be assessing whether he and his family had the stamina for a high-profile campaign so soon after the loss of his son to cancer.
Up until a day ago, the Washington rumour mill was spinning with talk that the vice-president was readying a bid, as reports suggested that staff were being interviewed for his campaign.
His decision not to stand in the Democratic race removes one of the biggest potential threats to Hillary Clinton, who faces strong challenges in the early voting states of Iowa and New Hampshire from self-professed socialist senator Bernie Sanders.
Clinton criticism
While ruling himself out as a competitor, the vice-president still took a swipe at Ms Clinton in his speech.
Without naming his former cabinet colleague, he challenged her remarks in last week’s Democratic debate that she considered Republicans her enemies.
“I don’t think we should look at Republicans as our enemies,” he said.
“They are our opposition, they are not our enemies, and for the sake of our country, we have to work together,” he said.
Outlining a checklist of policies, Mr Biden named goals that the Obama administration hopes to achieve in its last 15 months in power, as well as dreams he would hope to achieve if elected to the nation’s highest office.
“If I could be anything, I would have wanted to be the president that ended cancer, because it’s possible,” he said.
The former Delaware senator has run for the presidency twice.
His first bid in 1988 collapsed following allegations of plagiarism in speeches, while his campaign in 2008 failed to catch fire and he dropped out of the race early.
“Joe Biden would have been a strong candidate, but he waited too long to make a decision,” Democratic strategist Brad Bannon said.
“This is a big win for Hillary Clinton. She has been doing very well on the heels of the Democratic debate last week and she draws from the same well as Biden: older, Democratic establishment voters.
“When you see the next round of polls, you’ll see her with an even bigger lead.”
