After soaring to second place in the GOP field following the last Republican presidential debate, held a month ago, former Hewlett-Packard CEO Carly Fiorina has now fallen back to the bottom of the pack, according to a new CNN/ORC poll.

Tied in seventh, Fiorina is now polling at just 4 percent among Republican and Republican-leaning voters, down 11 points from the 15 percent support she received last month in a CNN poll.

"Fiorina's decline comes across the demographic and political spectrum, with her support now topping out at 8 percent among those with college degrees. Last month, she stood at 22 percent among the same group," wrote CNN's polling director Jennifer Agiesta. "Fiorina has dropped 11 points among women and 12 points among men, fallen 18 points among independents, 17 points among those age 50 or older, and 15 points among conservatives."

Fiorina surged to second place immediately following her debate performance, but that same debate performance could now be contributing to her decline. During the debate, Fiorina focused on Planned Parenthood and made claims about seeing an abortion video that fact-checkers later revealed did not exist.

A Fox News poll released last week also found Fiorina's support declining to 5 percent, down from 9 percent the previous month. In a similar NBC News/Wall Street Journal poll released this week, Fiorina finished in sixth place with 7 percent support. However, Fiorina's support did grow from 4 percent to 6 percent in a CBS survey released Oct. 11, showing just how unpredictable opinion surveys can be.

Overall in the latest CNN poll, billionaire real estate mogul Donald Trump continues to lead the field with 27 percent, followed by retired neurosurgeon Ben Carson with 22 percent, up 8 points from last month's poll. The two are tied at 23 percent support among registered Republican women, while Fiorina got 6 percent support.

Trailing Carson is former Florida Gov. Jeb Bush and Florida Sen. Marco Rubio, who each earned 8 percent. Former Arkansas Gov. Mike Huckabee and Kentucky Sen. Rand Paul come next at 5 percent, followed by Fiorina, who tied with New Jersey Gov. Chris Christie and Texas Sen. Ted Cruz with about 4 percent each.

The CNN telephone poll was conducted Oct. 14-17 among 465 registered Republican voters and right-leaning independents. It has a margin of error of plus or minus 4.5 percentage points.

Republicans will have another chance to prove themselves in the next GOP primary debate on Oct. 28.