The CNN debate methodology, released earlier this year, weighs polls from July 16 to Sept. 10.  

The use of the earlier surveys will hurt the former CEO of Hewlett-Packard, who barely registered in the polls before the Aug. 6 Fox News debate. But since then, she has seen a significant bounce.  
“It acts as sort of an anchor on those people who had done poorly early and a bit of a parachute for those people who have done well early,” said Cliff Zukin, a Rutgers University political scientist and former president of the American Association for Public Opinion Research. 

The criteria could also protect Sen. Rand Paul (Ky.) from sliding out of the top 10 despite his recent dip in polls.

Fiorina received 1 percent support or less in most of the polls before the Fox News debate. After a strong performance at Fox’s second-tier debate, her numbers began to climb, jumping to 5 percent. campaign and supporters hope she can maintain polling numbers high enough to make CNN’s top 10.