Why Joe Biden isn't running for president

After months of flirtation with a potential run, Vice President Joe Biden said Wednesday that he would not seek the Democratic presidential nomination in 2016.

For Biden, there were a number of personal and practical reasons why he decided not to launch a third bid for the presidency.

He was still toiling emotionally after the recent death of his son, former Delaware Attorney General Beau Biden. He was lagging behind in polls of the Democratic primary race. And he would have had a distinct challenge in building up the type of fundraising and infrastructure his would-be rivals had amassed.

"I know from previous experience that there is no timetable for this process," Biden said from the Rose Garden Wednesday, referring to the grief over his son's death. "The process doesn't respect, or much care about things like filing deadlines, or debates and primaries and caucuses."

And Biden also faced a number of practical campaign obstacles that would have made a campaign a distinct challenge. For one, he lacked the organization to rival the top Democratic candidates, former US Secretary of State Hillary Clinton and US Sen. Bernie Sanders (I-Vermont).

Biden would have needed to quickly hire key staff that would have been at a significant disadvantage against Clinton, who has built a vast organization even before announcing her candidacy in April. Her campaign has more than 500 staffers on its payroll, according to recent filings with the Federal Election Commission.

Biden also lacked money while Clinton's fundraising hauls have dwarfed every other competitor in the 2016 field. He would have had to move quickly to build a donor base that would help him amass funding on par with Clinton and Sanders, who raised only slightly less than Clinton in the last fundraising quarter.

"It is much more likely that the factors of him not getting into this race are money, whether he can get the organization up, and actual electoral pathway to victory," Rodell Mollineau, a long-time Democratic operative, told Business Insider last week.

And the electoral picture was also looking bleak for the vice president.

Recent polls conducted after Clinton's strong performance in the first Democratic debate showed the former secretary of state's numbers rising, while Biden's fell. A recent NBC/Wall Street Journal poll showed Biden garnering 15% support among Democratic voters nationally, while an ABC poll released Wednesday found it hovering at 16%.

Biden's strategy largely would've banked on winning in South Carolina, where his support among black voters would've helped him make up ground against Sanders, who has thus far failed to make serious inroads with minority voters.

Still, he would have had to catch up with Clinton, who has also focused significant energy on South Carolina. She also maintains an enormous advantage among minority voters, who made up the majority of Democratic primary voters in the state in 2008.

Biden appeared to acknowledge these challenges during his speech Tuesday, saying that it was likely too late to mount a serious bid for the nomination.

"Unfortunately, I believe that we're out of time. The time necessary to mount a winning campaign for the nomination," Biden said.

Finally, there was also another, more optimistic reason why Biden said that he ultimately decided to opt out of the race: The opportunity to more forcefully pursue a cure to cancer, which took his son's life, during his remaining time in the White House.

"I'm going to spend the next 15 months in this office trying to accomplish this," Biden said.

He added: "If I could be anything, I would've wanted to be the president who ended cancer."