(CNN) -- GOP front-runner John McCain is heading to Washington to try to convince a conservative-rich conference that he's their man.
Sen. John McCain has emerged as the front-runner in the race for the GOP presidential nomination.
Despite big wins in the Super Tuesday contests, McCain has yet to secure the support of his party's conservative side.
McCain, Mitt Romney, Mike Huckabee and Ron Paul are all to speak during the three-day Conservative Political Action Committee conference.
"Our message will be that we all share common principles, common conservative principles, and we should coalesce around those issues," the Arizona senator said Wednesday.
The conference is the country's largest annual gathering of activists, students and policymakers, according to CPAC. Watch McCain talk about his "conservative convictions" »
Last year, McCain was the only major Republican candidate to reject an invitation to speak to at the conference.
The Arizona senator, up against conservative backlash, will address the group Thursday. His critics say he's too liberal to carry his party's nomination, citing him breaking with the party on immigration, opposing the Bush tax cuts and co-sponsoring legislation on campaign finance reform. Watch what McCain says about his relationship with conservatives »
"I do hope that at some point we would just calm down a little bit and see if there's areas that we can agree on for the good of the party and the good of the country," said McCain, who's been known to reach across the aisle at times.
Comments like those caused some conservative talk-radio hosts to light into to McCain a day after Super Tuesday gave him a commanding lead and put him more than halfway to the number of delegates needed for the nomination. Watch how conservative McCain's record is »
"When did the measure of conservatism, when did the measure of success, when did the measure of progress, when did it become reaching out to Democrats?" Rush Limbaugh said on his show Wednesday.
"Why is it so hard to understand that what we want is to defeat those people? We view those people as threats to the American way of life, as we've always known it. We view liberals as a threat to the founding of this country," he said.
Laura Ingraham also expressed disdain over McCain's victories on her show.
"McCain has so radicalized key conservatives that some have vowed to turn themselves into suicide voters next November by pulling the lever for Hillary Clinton," she said.
McCain is a conservative, just not always a politically correct conservative, said CNN senior political analyst Bill Schneider.
"He's a conservative, he's been a conservative for a long time, but on occasion he departs from the conservative orthodoxy," Schneider said.
"He is now advertising his ability to make bipartisan deals on issues because that's what voters seem to want this year," he said.
But McCain did win key GOP states like California and Missouri this week. In the all important Super Tuesday contests, McCain took at least 504 delegates, compared to 175 for Romney and 141 for Huckabee.
Less than half -- 49 percent -- of Tuesday's voters who said they voted for McCain described themselves as conservative, exit polls from the 15 states holding GOP contests showed.
McCain says he's confident he can bring the party together, telling supporters, "We will unite the party behind our conservative principles and move forward and win the general election in November."
He said he's not worried that some "very conservative" Republicans don't think he is conservative enough. Watch McCain explain why he's the conservative »
"With conservative voters, which are the majority of Republicans, we did extremely well," he said.
Comparing his home state with that of his more conservative rival, he said, "We won by a much larger margin in Arizona than Gov. Romney did in Massachusetts."
"Is there a lot of work to unite the entire party?" he asked rhetorically. "Sure. After the campaigns are over, you've always got the task of uniting the party behind the nominee."
But he expressed confidence he can do just that. "Our message will be we all share common conservative principles," he said. "Fundamental conservative political philosophy, which has been my record."
According to exit polls, Republican voters who identified themselves as conservatives preferred Romney to McCain -- 38 percent to 31 percent -- with 24 percent choosing Huckabee.
Conservatives made up 63 percent of the Republican primary voters. McCain was the clear favorite among GOP voters who identified themselves as moderates and liberals, winning 54 percent and 56 percent of those groups, respectively.
Moderates made up 27 percent of Republican primary voters, and 10 percent said they were liberals.
Romney, who tried to rally conservatives disenchanted with McCain, may have been the big loser Tuesday, said Gloria Borger, a CNN senior political analyst.
"This is not a great showing for Mitt Romney. Obviously Huckabee has upstaged him. Huckabee upstaged him in the South. Huckabee upstaged him in every way," Borger said.
And unlike Romney, Huckabee is speaking out against Republicans who say they won't rally behind McCain if he's the nominee.
"There's no way that they can call themselves conservative and do that," he said on CNN's "American Morning." You know, some people need to switch to decaf."
The battle for the Republican nomination now shifts to Louisiana and Washington state, where voters will cast ballots on Saturday. GOP voters cast ballots next Tuesday in Maryland, Virginia and Washington, D.C. E-mail to a friend
CNN's Dana Bash, Carol Costello and Bill Schneider contributed to this report.