This story has been updated.

GOP presidential candidate Scott Walker -- who has tumbled from top-tier status amid tepid debate performances and other missteps -- will pull back from other early-voting states in favor of a heavy focus on Iowa, where he once led the field and has strong roots as a Midwesterner.

The Wisconsin governor also faces growing pressure from some financial backers to make staffing changes in an attempt to turn around his campaign. But in a brief interview with The Washington Post at the Los Angeles airport Thursday afternoon, Walker said he had just completed a conference call with about 80 major donors -- none of whom mentioned wanting staff changes.

"It didn't come up at all," Walker said, as he waited for a flight to Detroit.

Instead, Walker discussed Wednesday night's debate and his strategy to spend much more time in Iowa, insisting that the campaign is still strong, according to three people on the call.

Several of Walker's supporters said his performance in Wednesday's second GOP debate in Simi Valley, Calif., was stronger than the first debate in Cleveland, where he largely disappeared into the heavy field. Yet supporters were also angry at CNN moderators for asking Walker only three questions during Wednesday's 3-hour debate, contributing to Walker finishing last in the amount of time he spoke on stage.

The debate includes bashing Donald Trump, a fiery Carly Fiorina and an admission from Jeb Bush that he says his mom won't like. (CNN)

Walker told The Post that he felt good about his debate performance, though he acknowledged the debate was long and the stage was at times uncomfortably hot under the bright lights.

Some of those on Thursday's donor call had expected different news. Many backers have directed their ire at campaign manager Rick Wiley, who some Walker supporters believe expanded the staff too quickly and has failed to calibrate spending during the summer fundraising season. A recent count put the number of full-time Walker campaign staff at around 90, and there have been no cutbacks in salaries as there were earlier this summer in former Florida governor Jeb Bush's operation.

"There is a substantial amount of chatter that he needs to go," said one major Walker fundraiser, requesting anonymity to discuss private conversations. "People are worried."

But it became clear on Thursday afternoon that Walker is not ready to make that sort of change. Walker aides, who declined to comment on the record, dismissed the idea of a management shake-up.

"I'm not going anywhere," Wiley told the Capital Times on Thursday. "The vicious rumor cycle has begun. Reports of my demise are greatly exaggerated." He did not respond to requests for comment from The Post.

Angst has built among Walker's top fundraisers and donors in the last two weeks as his poll numbers have plummeted in Iowa and nationwide. Stanley S. Hubbard, a Minnesota media mogul and top Walker donor, said that while he is sticking with Walker for now, he is considering also giving money to Sen. Marco Rubio (Fla.), former Hewlett-Packard chief executive Carly Fiorina and New Jersey Gov. Chris Christie. All performed well at Wednesday's debate, he said.

"I think I might help some other candidates too," Hubbard said. "There might be some good candidates."

Donors have started holding spontaneous conference calls, patching a half-dozen people together on the phone to try to game out what the governor should do. Several supporters said they would like to see the campaign add Keith Gilkes, a longtime Walker confidant who ran his gubernatorial campaigns and is now heading the pro-Walker super PAC. Gilkes traveled to New York a couple weeks ago to meet with major fundraisers and relay some of his concerns about the direction of the campaign, according to three people with knowledge of the meetings.

Gilkes dismissed talk that he is headed for the campaign and said he remains focused on using the resources of the super PAC to sell the governor to voters.

"I think it's a very sensationalized story that has no truth to it," Gilkes said. "I think it's steady as she goes... I am fully committed to the Unintimidated PAC. We have a strategy, and I fully intend to execute that strategy to help the governor become the Republican nominee."

Walker's performance as a candidate has contributed to questions about the trajectory of his campaign. His verbal missteps -- often the result of answering questions on the campaign trail with responses that he is forced to amend and later clarify -- have been a topic of concern among his own loyalists. Last month, he twice found himself forced to clarify something he had said, first on whether he supported an end to birthright citizenship and again after an offhand answer suggesting he favored building a wall on the U.S.-Canadian border.

Walker has been urged repeatedly to be far more careful in answering unexpected questions, which have overshadowed positive reviews he's gotten from conservative media and commentators about some of his policy proposals.

Some backers also fear that, as a result of his drop in the polls, he has adopted a persona that doesn't square with his low-key demeanor and personality. As one person who has known him for some years put it, the tough-guy approach -- including his recent promises to "wreak havoc" on Washington -- is not a good fit.

When asked Thursday on Fox News's "America's Newsroom" if he was thinking about making any changes to his campaign, Walker skirted the question.

"For us, the biggest thing to get is that grassroots," he said. "You know Ronald Reagan was behind in the polls in 1980... He went forward and obviously won that election and brought about one of the best presidencies we've had I think in modern American history."

Walker advisers defend his position in the race, arguing that he is still liked by voters.

"What we watch is: Where's his favorable, where's his unfavorable?" said senior adviser Ed Goeas after Wednesday night's GOP debate. "In survey after survey, with the exception of Ben Carson, he has the highest favorable ratio of all the candidates. If this was something where voters were reacting negatively to him, you'd see that go down."

Goeas said he spoke last week to two dozen elected officials in South Carolina supporting Walker and did not hear any nervousness.

"I walked through where our Iowa poll was compared to the others," he said. "I walked through what we were planning to do over the next couple of months. And there were no weak knees in the room. In our polling in Iowa, we have a 79-10 favorable rating."

Republicans knowledgeable about Walker's campaign said officials are planning to double down in Iowa and ship more staff there to rebuild Walker's support. The campaign hopes to double Walker's time in Iowa, from about five days per month to 10 days per month, while also leaving time to continue fundraising for the campaign.

Some supporters have taken solace in an internal poll showing Walker leading in Iowa by a sizable margin among Republicans who participated in the 2012 GOP caucuses. Still, their hopes that Walker would have a breakout performance at Wednesday's debate did not materialize. While many felt he was stronger than he was in the first forum, they were frustrated by his tentative approach to the free-wheeling format and unwillingness to jump in the fray.

Many prominent Walker bundlers came away from the debate uncertain who will eventually emerge as the leader in the crowded field.

Hubbard, the major donor in Minnesota, said he likes what he is hearing from Walker and he doesn't understand why his pitch "doesn't turn people on."

"I think Walker says all the right things," he said, but "something's missing in the demeanor."

Philip Rucker, Jose A. DelReal, David Weigel, Sean Sullivan and Dan Balz contributed to this report.