Connecticut Sen. Joe Lieberman may be some Republicans' idea of a good Democrat, but a growing number of fellow party members in his home state couldn't disagree more.

"It's at the point where he's no longer interested in his own party's opinion, he's really out of touch with reality," said Mitchell Fuchs, chairman of the Fairfield Democratic Town Committee in Connecticut. "For me, he's crossed the line a number of times."

Passions flared after Lieberman's recent trip to Iraq. Upon his return, the three-term senator pointed to what he views as progress on the ground there and suggested that Democrats should avoid harsh criticisms of President Bush's Iraq policy.

In turn, Republicans and administration officials, including Bush, used the senator's comments to bolster their case for war and underscore Lieberman's differences with other Democratic leaders on the issue. Republicans have since charged that Democrats lack a coherent, unified message on Iraq.

The series of events has sparked petitions and protests outside of Lieberman's district office in Hartford and prompted a potential challenge from a former and formidable political foe.

In an interview with FOXNews.com, former U.S. senator and Connecticut Gov. Lowell Weicker said he will challenge Lieberman in 2006 if no credible anti-war Democrat or Republican jumps into the race first.

"I'm not going to let [Lieberman] get a free pass on this. And that's what's going to happen if no one steps up to bat," said Weicker, who as a Republican lost his Senate seat to Lieberman in 1988. In 1990, Weicker went on to become governor, elected as an independent.

Weicker, 74, said he would run for Senate against Lieberman as an independent, not a Democrat. He said he has been against the war in Iraq "from the onset," and doesn't take lightly the notion of coming out of retirement to challenge the incumbent.

"I have no desire to put my neck on the chopping block. I'm in the business of winning," he said.

Meanwhile, a letter with 55,000 signatures β€” mostly from out of state β€” was delivered to Lieberman's district office in Hartford last Tuesday urging the senator to stop "trying to stifle debate" on war policy and join "the majority of Americans in questioning President Bush's foreign policy."

The group circulating the letter, Democracy for America, is led by Jim Dean, a Connecticut resident and brother of Democratic National Committee Chairman Howard Dean.

On top of that, Democrats attending the regular State Central Committee meeting last Wednesday criticized Lieberman and called for support for a primary challenge against him at the party's convention in May.

"I speak to Democratic state senators all the time. They always said, 'Joe is a rat, but he's our rat.' Now they are saying, 'Joe's a rat and we can't afford to have him at the top of our ticket,'" said Democrat Keith Crane of Branford, Conn. "I think Joe is going to get a rude awakening in May."

Crane runs DumpJoe.com, one of a handful of anti-Lieberman sites that have cropped up in recent years. He said Democrats see Lieberman as increasingly out of touch with his constituency, the majority of whom are Democrats and voted against Bush in the last two presidential elections. In 2004, Democratic presidential candidate Sen. John Kerry beat Bush in Connecticut 54 percent to 43 percent.

Crane said many Democrats hope to persuade Weicker to run in their party's primary.

"This has to be a grassroots thing," he said.

Lieberman has been known to buck his party before β€” in 1998, he was one of the only major Democrats to rebuke publicly then-President Bill Clinton for his sexual relationship with Monica Lewinsky. He has previously sided with Republicans on many economic and foreign policy issues.

Lieberman's office did not respond to FOXNews.com in repeated calls for comment, but the senator still has supporters among the state party leadership, and they say they are part of the moderate majority in the state. Audrey Blondin, a longtime friend and political supporter of the senator, says she wouldn't want him any other way.

"I respect Joe, he has never been afraid to say what he thinks and explains in detail why he thinks that way. He's not one who is swayed by public opinion," said Blondin, who is a member of the Democratic State Central Committee. Blondin said she shares her fellow Democrats' harsh opinion of the Bush administration on the war, but respects Lieberman's position.

Jim Diamond, also a member of the State Central Committee, representing Stamford, Lieberman's hometown, agreed with Blondin.

"Joe Lieberman has made a career out of acting in a bipartisan fashion. He's been the lead Democrat on fighting terrorism and homeland security and for that he gets a lot of support across both sides of the political aisle," Diamond told FOXNews.com.

"I think [critics] are in the minority," he said. "Often it’s the people on the extremes of the political spectrum who make the most noise."

But Fuchs of Fairfield and Crane say a growing number of local Democratic leaders are vocalizing their dissatisfaction with Lieberman, and support for a primary challenge is growing.

"I've talked to town [Democratic committee] chairs all over the state, and I would say many of them are getting upset with [Lieberman]," said Fuchs. Meanwhile, the Democratic town committee in Manchester is set to pass a resolution in early 2006 withdrawing its support for Lieberman, according to reports.

Democrats interested in defeating Lieberman in a Democratic primary say they will continue to court Weicker. But they may find Weicker unreceptive, as he said he is also unhappy with the Democrats' lack of veracity on the war issue.

"My criticisms are probably as stiff against the Democrats as they are against the Republicans," Weicker said, adding, "As much as I disagree with the Republican policy, I couldn't disagree more with the deafening silence on behalf of the Democrats on the war."

Running as an independent, he said, "allows me the integrity of my position, which is, I'm not happy with either side."

Asked about Democratic concerns that by running as an independent, Weicker could split the Democratic vote and end up giving Connecticut a pro-war Republican senator, he responded, "Their problem is not my problem. My problem is to get elected."

Most political observers say that Lieberman still remains a tough man to beat, despite the recent rancor.

"I think he has a safe seat right now because there is no one really with the ability to challenge him," said Gary Rose, political science professor at Sacred Heart University in Fairfield.

Lieberman won his last two Senate elections by large margins, even in 2000 when he was running unsuccessfully as Al Gore's vice president.

Weicker could change that, Rose said, suggesting that he has the political stature, the fundraising capability and the reputation as an independent to pose the perfect challenge.

"[Weicker] has all the ingredients that's needed to unseat an incumbent. He has a sizable following in this state and he's right on the issue of Iraq," according to a majority of people in the state, Rose said.

Diamond said he doesn't agree and believes that Lieberman, who steers a moderate course, appeals to both Democrats and Republicans and is not as vulnerable as some would suggest. He also won't concede that a majority of Connecticut voters are against the war.

"If it turns out to be a 1988 rematch between Weicker and Lieberman, I have no doubt the senator will be victorious," Diamond said.