A Fox News poll released Wednesday found Gov. Rick Perry's support has dropped 10 percent in the last month to 19 percent, while Mitt Romney leads the pack with 23 percent support.
Romney sat at 22 percent last month.
The candidate to make the biggest push in the new poll was Herman Cain, whose support has nearly tripled to 17 percent since this month's debates and his win in the Florida Republican Party's straw poll last Saturday.
Newt Gingrich held the fourth spot with 11 percent, and all other candidates were in single digits.
Michele Bachmann now garners only 3 percent support, down from a high of 15 percent in July.
The poll was based on live phone interviews with a national sample of 925 registered voters.