In a speech Wednesday Vice President Joe Biden announced he will not be running for president, citing his son's recent death and the fact that the grieving process has closed "the window on mounting a realistic campaign."
Most notably? Money—as Harry Enten at FiveThirtyEight points out.
In order to match the funds raised by Democratic frontrunner Hillary Clinton, Biden would need need to drum up $33 million in cash. That doesn't even count the nearly $16 million Clinton has available via PACs and super PACs. Altogether, that's "a lot of money that can be used for advertising, direct mail, staff, travel, etc," Enten notes.
Funding aside, there's been weak voter support for Biden making a late entry into the race: A recent NBC poll found that 38% of Democratic primary voters said they would prefer Biden not run, while only 30% said they wanted him to and 31% said they had no opinion.