US Vice President Joe Biden speaks with in the Rose Garden at the White House on October 21, 2015, in Washington, DC, where he announced that he is not running for president. (AFP)
Republican presidential candidates including Donald Trump applauded Joe Biden's decision today not to enter the 2016 race, saying Democrats are now stuck with their unpopular frontrunner Hillary Clinton.
Democrats lined up to heap praise on the veteran politician, who dashed supporters' hopes when he acknowledged that the window had closed for him to mount a successful presidential campaign.
Clinton, the former secretary of state and the Democrat with the most to lose from a Biden run, hailed him as "a good friend and a great man."
"History isn't finished with Joe Biden," she said, adding that "if I know Joe, he will always be on the front lines, always fighting for all of us."
Republicans made no secret of their excitement about Biden's announcement, however.
"I think Joe Biden made correct decision for him & his family," Republican frontrunner Trump, the bombastic billionaire real estate tycoon, posted on Twitter.
"Personally, I would rather run against Hillary because her record is so bad."
The Republican National Committee's chairman, Reince Priebus, essentially echoed Trump, declaring Biden as "the most formidable general election candidate the Democrat Party could have fielded."
"The vice president's decision not to enter the 2016 race is a major blow for Democrats, who now will almost certainly be saddled with their unpopular and scandal-plagued front-runner Hillary Clinton," Priebus said.
Biden's no-go "greatly improves our chances of taking back the White House."
Polls show it would improve Clinton's chances of winning the nomination.
Biden has been polling competitively in national surveys, but when he is not part of the equation, support for Clinton tended to rise at the expense of her chief rival Senator Bernie Sanders, an independent who describes himself as a democratic socialist.
"Democrats are now left with a socialist or a candidate under FBI investigation," said Louisiana governor and Republican candidate Bobby Jindal, referring to the probe into Clinton's use of a private email account and server while she was secretary of state.