House Republicans greeted Sen. John McCain (R-Ariz.) with a standing ovation at a closed conference Wednesday morning and later publicly endorsed him in an effort to send a clear message of party unity.

Those who attended the meeting said they believe McCain will be the last candidate standing, even though former Arkansas Gov. Mike Huckabee is still in the race.

Minority Leader John Boehner (R-Ohio) admitted he has had differences with McCain in the past, but said that McCain’s unwavering support of Iraq war funding, his stance against abortion rights and his service to the country trumped any past disagreements.

Boehner also credited McCain with helping buy “political time” to allow Iraq to make progress.

“I’m proud to endorse my colleague, proud to endorse my friend John McCain,” Boehner said.

GOP conference Chairman Adam Putnam (Fla.), once a backer of former Sen. Fred Thompson (R-Tenn.), also gave McCain the nod Wednesday.

Last week, Rep. Eric Cantor (R-Va.) endorsed McCain, a move that some political observers said may have helped clinch his Tuesday victory in Virginia.

According to a source in the room, the brief question-and-answer period was civil, and questions ranged from immigration to earmarks.

McCain campaign manager Rick Davis, who spoke later with reporters at a lunch hosted by The Christian Science Monitor, said the discussion was more a “coming together” than a policy discussion.

Davis insisted that McCain is still in “primary mode,” and said the campaign will aim to secure the nomination on March 4, when Texas and Ohio vote.

Davis said he calculates that McCain needs to win 70 of Texas’s 138 delegates, which are winner-take-all by congressional district. That would allow McCain to “slice and dice” the state by district. The same cannot be said for Huckabee, Davis added.

“I can look at Texas and say, ‘Where can I get my 70?’ ” Davis said. “If Gov. Huckabee wants to go compete in a couple places in Texas, knock yourself out.”

Davis declined to criticize Huckabee directly, insisting that his continued run forces the media to continue to cover the McCain campaign instead of focusing entirely on the fierce Democratic contest.

But he said he would like to see the senator wrap up the nomination sooner rather than later.

“The sooner that happens, the better off it is for all of us,” Davis said. “I’m not encouraging anybody to stay in the race and contest it.”

Some questions at the lunch also touched on the rise of Sen. Barack Obama (D-Ill.) and the possibility that he will be McCain’s general election rival.

Davis mostly focused on the two-person race between Obama and Sen. Hillary Rodham Clinton (D-N.Y.), but conceded that he considers Obama a “political phenomenon.” He added that he was not “intimidated” by Obama’s ability to put 17,000 people in an arena, because he did not know how that would translate into the general election.

Davis offered a warning to Obama of sorts, mentioning that the National Journal had rated Obama the most liberal senator.

“I don’t know if all 17,000 people who were in his audience knew about that,” Davis said. “But they will.”

On the issue of public financing, Davis said McCain would accept it for the general election on the condition that Obama would do the same. He suggested that the Illinois senator may opt out, given his fundraising prowess.

“If I was raising $35 million a month, I’d think that through,” said Davis. “There’s a more likely case that [Obama] will break his pledge [to accept public funds] than John.”

As for McCain’s fundraising, Davis acknowledged he has a lot of work to do, adding that he continues to run “a budget campaign.”

“We’ve got to get the Republican Party excited about this candidacy,” Davis said.