CNN Debate Rules Would Give Biden a Chance to Appear

CNN has announced its criteria for the October 13 Democratic debate, making clear that Vice President Joe Biden would be eligible to participate if he announces a late run for president as late as the day of the event.

According to the rules, eligible candidates must have either filed a statement of candidacy for the presidency or publicly stated that such a statement will be made by October 14 -- the day after the debate.

Each candidate must also have received an average of at least one percent in a combination of three reputable national polls between August 1 and October 10, 2015.

Five of the declared Democratic presidential candidates -- Hillary Clinton, Bernie Sanders, Martin O'Malley, Jim Webb, and Lincoln Chafee -- have been invited to participate.

The debate is scheduled for 9pm ET on October 13 in Las Vegas, Nevada.