Washington (CNN) Carly Fiorina shot into second place in the Republican presidential field on the heels of another strong debate performance, and Donald Trump has lost some support, a new national CNN/ORC poll shows .

The survey, conducted in the three days after 23 million people tuned in to Wednesday night's GOP debate on CNN, shows that Trump is still the party's front-runner with 24% support. That, though, is an 8 percentage point decrease from earlier in the month when a similar poll had him at 32%.

Fiorina ranks second with 15% support -- up from 3% in early September. She's just ahead of Ben Carson's 14%, though Carson's support has also declined from 19% in the previous poll.

Driving Trump's drop and Fiorina's rise: a debate in which 31% of Republicans who watched said Trump was the loser, and 52% identified Fiorina as the winner.

During the CNN debate, Fiorina clashed with Trump over his personal attacks and their business records and scored points for her condemnation of Planned Parenthood.

The top three contenders underscore a key theme in the 2016 race: In a jampacked GOP presidential field, the leading candidates are the only ones who have never held political office.

Photos: Carly Fiorina's political career Photos: Carly Fiorina's political career Former business executive Carly Fiorina speaks to guests gathered at the Point of Grace Church for the Iowa Faith and Freedom Coalition 2015 Spring Kickoff on April 25, 2015, in Waukee, Iowa. Hide Caption 1 of 15 Photos: Carly Fiorina's political career Fiorina prepares to speak to guests gathered at the Point of Grace Church for the Iowa Faith and Freedom Coalition 2015 Spring Kickoff on April 25, 2015, in Waukee, Iowa. Hide Caption 2 of 15 Photos: Carly Fiorina's political career Fiorina speaks to guests gathered at the Point of Grace Church for the Iowa Faith and Freedom Coalition 2015 Spring Kickoff on April 25, 2015, in Waukee, Iowa. Hide Caption 3 of 15 Photos: Carly Fiorina's political career Fiorina greets guests at the Johnson County Republicans Spaghetti Dinner at Clear Creek Amana High School on April 24, 2015, in Tiffin, Iowa. Hide Caption 4 of 15 Photos: Carly Fiorina's political career Fiorina, right, poses for a selfie with Joe Koberna at the Johnson County Republicans Spaghetti Dinner at Clear Creek Amana High School on April 24, 2015, in Tiffin, Iowa. Hide Caption 5 of 15 Photos: Carly Fiorina's political career Fiorina speaks at the First in the Nation Republican Leadership Summit April 18, 2015, in Nashua, New Hampshire. Hide Caption 6 of 15 Photos: Carly Fiorina's political career Fiorina speaks during a forum on Capitol Hill March 16, 2015, in Washington. Fiorina spoke about what she calls the War on Women in politics. Hide Caption 7 of 15 Photos: Carly Fiorina's political career Fiorina delivers remarks at a discussion called "Welcoming Every Life: Choosing Life after an Unexpected Prenatal Diagnosis, focusing on caring for children with Down Syndrome," organized by the Heritage Foundation and the National Review Institute in Washington on January 20, 2015. Hide Caption 8 of 15 Photos: Carly Fiorina's political career Fiorina concedes defeat to her rival Sen. Barbara Boxer, D-California, during a news conference at her Irvine campaign headquarters on November 3, 2010, in Irvine, California. Hide Caption 9 of 15 Photos: Carly Fiorina's political career Fiorina, left, watches election results with granddaughter Kara Tribby, 7, in her hotel room at the Hyatt Regency Irvine, November 2, 2010, in Irvine, California. Hide Caption 10 of 15 Photos: Carly Fiorina's political career Fiorina, left, puts on headphones before participating in a radio debate with incumbent U.S. Sen. Barbara Boxer, D-California, in Washington, as co-moderator Gabriel Lerner, metro editor of La Opinion, does the same at local public-radio affiliate KPCC studios September 29, 2010, in Pasadena, California. Hide Caption 11 of 15 Photos: Carly Fiorina's political career Fiorina arrives for a news conference after participating in a debate with U.S. Sen. Barbara Boxer, D-California, in a radio debate hosted by La Opinion and public radio station KPCC on September 29, 2010, at the KPCC studios in Pasadena, California. Hide Caption 12 of 15 Photos: Carly Fiorina's political career Boxer, left, and Fiorina, center, greet moderator Randy Shandobil, right, after a debate on the campus of Saint Mary's College September 1, 2010, in Moraga, California. Hide Caption 13 of 15 Photos: Carly Fiorina's political career Fiorina, left, smiles with her husband Frank Fiorina, right, after casting their ballots at a polling place June 8, 2010, in Los Altos Hills, California. Hide Caption 14 of 15 Photos: Carly Fiorina's political career Fiorina greets supporters after announcing her candidacy for U.S. Senate at Earth Friendly Products packaging plant on November 4, 2009, in Garden Grove, California. Hide Caption 15 of 15

But one established politician has seen his standing rise after flashing foreign policy chops on the debate stage. Sen. Marco Rubio of Florida -- identified as Wednesday's winner by 14% of Republicans, putting him second behind Fiorina -- is now in fourth place with 11% support, up from 3% in a previous poll.

In fifth place is former Florida Gov. Jeb Bush, at 9%. He's followed by Sen. Ted Cruz of Texas and former Arkansas Gov. Mike Huckabee at 6% each, Sen. Rand Paul of Kentucky at 4%, New Jersey Gov. Chris Christie at 3%, Ohio Gov. John Kasich at 2% and former Sen. Rick Santorum of Pennsylvania at 1%.

Five other candidates received less than one-half of 1 percentage point support: former Virginia Gov. Jim Gilmore, Sen. Lindsey Graham of South Carolina, Louisiana Gov. Bobby Jindal, former New York Gov. George Pataki and Wisconsin Gov. Scott Walker.

Walker's collapse is especially stark.

Celebrated by conservatives -- in the party's base and its donor class alike -- for his union-busting efforts in Wisconsin, Walker at one point led the field in the key early voting state of Iowa.

His support had already dropped to 5% in a CNN/ORC poll in early September, but the bottom appears to have fallen out completely since then -- with a second flat debate performance coming after criticism of his disparate answers on issues like birthright citizenship.

Carson was a quiet presence in Wednesday's debate, but he remains the most popular candidate in the GOP field, with 65% of Republican voters saying they view him favorably, compared with just 10% saying they have an unfavorable opinion of the retired neurosurgeon.

Rubio ranks second in the popularity contest, with 57% viewing him favorably and 16% unfavorably. He's followed by Fiorina (54% favorable to 17% unfavorable), Huckabee (53% to 28% unfavorable), Cruz (52% to 22%) and Trump (52% to 40%).

Photos: Who's running for president? Photos: Who's running for president? Ted Cruz, Donald Trump, John Kasich, Hillary Clinton and Bernie Sanders, Hide Caption 1 of 6 Photos: Who's running for president?



"So, ladies and gentlemen, I am officially running for president of the United States, and we are going to make our country great again," Trump told the crowd at his announcement. Businessman Donald Trump announced June 16 at his Trump Tower in New York City that he is seeking the Republican presidential nomination. This ends more than two decades of flirting with the idea of running for the White House."So, ladies and gentlemen, I am officially running for president of the United States, and we are going to make our country great again," Trump told the crowd at his announcement. Hide Caption 2 of 6 Photos: Who's running for president?



"These are all of our stories," Cruz told the audience at Liberty University in Virginia. "These are who we are as Americans. And yet for so many Americans, the promise of America seems more and more distant." Sen. Ted Cruz of Texas has made a name for himself in the Senate, solidifying his brand as a conservative firebrand willing to take on the GOP's establishment. He announced he was seeking the Republican presidential nomination in a speech on March 23."These are all of our stories," Cruz told the audience at Liberty University in Virginia. "These are who we are as Americans. And yet for so many Americans, the promise of America seems more and more distant." Hide Caption 3 of 6 Photos: Who's running for president? Ohio Gov. John Kasich joined the Republican field July 21 as he formally announced his White House bid.



"I am here to ask you for your prayers, for your support ... because I have decided to run for president of the United States," Kasich told his kickoff rally at the Ohio State University. Hide Caption 4 of 6 Photos: Who's running for president?



"Everyday Americans need a champion, and I want to be that champion -- so you can do more than just get by -- you can get ahead. And stay ahead," she said in her announcement video. "Because when families are strong, America is strong. So I'm hitting the road to earn your vote, because it's your time. And I hope you'll join me on this journey." Hillary Clinton launched her presidential bid on April 12 through a video message on social media. The former first lady, senator and secretary of state is considered the front-runner among possible Democratic candidates."Everyday Americans need a champion, and I want to be that champion -- so you can do more than just get by -- you can get ahead. And stay ahead," she said in her announcement video. "Because when families are strong, America is strong. So I'm hitting the road to earn your vote, because it's your time. And I hope you'll join me on this journey." Hide Caption 5 of 6 Photos: Who's running for president?



"This great nation and its government belong to all of the people and not to a handful of billionaires, their super PACs and their lobbyists," Sanders said at a rally in Vermont on May 26. Sen. Bernie Sanders , an independent from Vermont who caucuses with Democrats, announced his run in an email to supporters on April 30. He has said the United States needs a "political revolution" of working-class Americans to take back control of the government from billionaires."This great nation and its government belong to all of the people and not to a handful of billionaires, their super PACs and their lobbyists," Sanders said at a rally in Vermont on May 26. Hide Caption 6 of 6

The biggest positive movement was in favor of Fiorina, whose favorability rating has climbed by 9 percentage points since August. And the biggest drop hit Trump, who shed 6 percentage points in that same period.

But Trump still stands out on the issues.

About 44% of likely GOP voters say they see Trump as the candidate who could best handle the economy -- well ahead of his nearest competitors: Fiorina at 11%, Rubio at 10% and Bush at 8%.

Trump also wins on immigration, with 47% saying he could best address the issue, ahead of second-place Rubio's 15% and Bush's 9%.

He even edges Rubio, 22% to 17%, on who could best handle foreign policy.

The poll offered some good overall news for Republicans: 65% of GOP voters said they are either "extremely" or "very" enthusiastic about voting in the 2016 presidential race, compared with 51% of Democrats.

The CNN/ORC poll was conducted September 17-19 and surveyed 1,006 adult Americans, including 924 registered voters -- 444 of whom are Republicans and independents who lean toward the GOP. The margin of error with the Republican results is plus or minus 4.5 percentage points.