ORLANDO, Fla. — Republican insiders are rising up to cut Newt Gingrich down to size, testament to the GOP establishment's fear that the mercurial candidate could lead the party to disaster this fall.

The gathering criticisms are bitingly sharp, as if edged by a touch of panic, a remarkable development considering the target once was speaker of the House and will go down in history as leader of the Republicans' 1994 return to power in Congress. The intended beneficiary is Mitt Romney, a once-moderate Massachusetts governor whom many rank-and-file Republicans view with suspicion.

"The Republican establishment might not be wild about Mitt Romney, but they're terrified by Newt Gingrich," said Dan Schnur, a former GOP campaign strategist who teaches politics at the University of Southern California.

The anti-Gingrich statements have come from conservative columnists, talk show hosts including Ann Coulter, former Reagan administration officials and others. One of the harshest was written by former Sen. Bob Dole, the party's 1996 presidential nominee.

"I have not been critical of Newt Gingrich but it is now time to take a stand before it is too late," Dole wrote in the conservative magazine National Review. "If Gingrich is the nominee it will have an adverse impact on Republican candidates running for county, state, and federal offices."

As speaker from 1995 through 1998, Gingrich "had a new idea every minute and most of them were off the wall," Dole wrote. He said he struggled against Democrats' TV attacks in his 1996 campaign, "and in every one of them, Newt was in the ad."

Gingrich has reacted unevenly to the accusations, sometimes denouncing them, other times wearing them like a badge of honor.

"The Republican establishment is just as much as an establishment as the Democratic establishment, and they are just as determined to stop us," he told a tea party rally Thursday in central Florida.

The crowd cheered. But lingering near the back was an example of how the Romney campaign is taking advantage of the whacks at Gingrich: GOP Rep. Jason Chaffetz of Utah. Chaffetz is beloved by many conservatives, and he goes from one Gingrich event to another to tell reporters why he thinks Romney would be a stronger challenger against President Barack Obama in the fall.

Gingrich aide R.C. Hammond confronted Chaffetz on Friday at an event in Delray, Fla., noting that some Republican officials criticize such shadowing tactics. Chaffetz defended his presence, saying Gingrich has vowed to show up everywhere Obama campaigns this fall, if several hours later.

Romney has drawn other high-ranking surrogates, with mixed results. South Carolina Gov. Nikki Haley annoyed some of her tea party supporters when she campaigned throughout her state for Romney, who lost to Gingrich by 12 percentage points.

It's unclear whether the anti-Gingrich push is driving a new wedge between establishment Republicans and anti-establishment insurgents such as the tea partyers.

"We don't like the Republican establishment anyway," said Mark Meckler, a Californian and co-founder of Tea Party Patriots. He said tea partyers are heavily focused on state and local races, and are wary of getting drawn into the presidential quarrels.

After all, Meckler said, "it's not as though Newt Gingrich hasn't been part of the Republican establishment."

Many other conservative activists also noted Gingrich's long history as a Washington insider, including 20 years in Congress and 13 as a well-paid consultant, writer and Fox News commentator. His history complicates his efforts to rally angry, working-class Republicans who feel that an "elite" cadre of officials, journalists and others look down on them.

"He's in one sense attacking the establishment he says he helped lead," said John Feehery, a former top House GOP aide who contends the tea party's influence is often overstated. The chief complaints about Gingrich focus more on his personality than his politics, which are hard to nail down, Feehery said.

The most damaging criticisms have come from former friends and colleagues who worked closely with him in Congress. It's Gingrich's egotistic behavior, more than ideology, that is driving the attacks, Feehery said.

Among those defending Gingrich are Sarah Palin, the 2008 vice presidential nominee who is admired by many tea partyers.

"Look at Newt Gingrich, what's going on with him via the establishment's attacks," Palin said this week on Fox Business Network. "They're trying to crucify this man and rewrite history and rewrite what it is that he has stood for all these years."

Palin and Rep. Michele Bachmann, who dropped out of the presidential race, are tea party favorites with minimal experience in Washington and in top GOP circles. Gingrich is trying to tap the sense of resentment among their followers. But his long and complicated Washington record and reputation for intra-party quarrels seem to leave some tea partyers unimpressed.

"It's truly a shame that this is where the Republican establishment has chosen to focus their energy," said Marianne Gasiecki, a tea party activist in Ohio. She added, however, that political activists should focus on congressional races. "If we have a conservative House and Senate," she said, "the power of the president is really insignificant."

As Gingrich's broadcast ads in Florida become more pointed, prominent Republicans are chiding him without endorsing Romney or any other candidates. Gingrich stopped running a radio ad that called Romney anti-immigrant after Sen. Marco Rubio, R-Fla., said it was unfair and damaging to the party.

So long as party insiders' complaints about Gingrich focus on his personality and quirks, the GOP can postpone a more wrenching debate about ideology, which may be in store if the once-moderate Romney is nominated. For now, conservative stalwarts seem determined to depict Gingrich as too erratic to be the party's standard bearer, let alone president.

Columnist Charles Krauthammer told Fox News: "Gingrich isn't after victory, he's after vengeance." He added: "This is Captain Ahab on the loose."

Some Republican voters are pushing back. "I want so badly to be for Gingrich, and I'm not going to be bullied out of my vote," said Barb Johnson, 52, who attended the tea party rally in Mount Dora, Fla., on Thursday. "I like his strong presence."

Florida's primary is Tuesday.