By John Whitesides, Political Correspondent
WASHINGTON (Reuters) - Mitt Romney ended his strugglingU.S. presidential bid on Thursday, clearing the way for JohnMcCain to become the all-but-certain Republican nominee andbegin mending fences with disgruntled party conservatives.
In an appearance before a conference of conservativeactivists, Romney said he was ending his bitter nominating duelwith McCain to allow Republicans to focus on a Novemberelection showdown with the eventual Democratic nominee, eitherSen. Hillary Clinton or Sen. Barack Obama.
"I feel I have to now stand aside, for our party and forour country," the former Massachusetts governor told theshocked crowd, some of whom gasped and shouted "no, no" inresponse.
McCain, who had built an almost insurmountable lead indelegates to the party's nominating convention, pleaded forparty unity during an appearance at the same conference a fewhours later.
"I know I have a responsibility, if I am, as I hope to be,the Republican nominee for president, to unite the party andprepare for the great contest in November," the Arizona senatortold the activists gathered in a Washington hotel.
"And I am acutely aware that I cannot succeed in thatendeavour, nor can our party prevail over the challenge we willface from either Senator Clinton or Senator Obama, without thesupport of dedicated conservatives," he said.
Romney pulled out after losing 14 of 21 states on Tuesday,the biggest day of U.S. presidential voting ahead of November'selection, while McCain romped to coast-to-coast wins andcemented his position as front-runner.
Former Arkansas Gov. Mike Huckabee, who won five states onTuesday, remains in the race but will have an almost impossibletask overcoming McCain, who has rolled up more than 700 of the1,081 delegates needed to win the nomination.
McCain, the 71-year-old former Vietnam prisoner of war, hasbecome a target of critics on the right for his moderate viewson illegal immigration, his votes against President Bush's taxcuts in 2001 and 2003 and his labelling in 2000 of somereligious conservative leaders as "agents of intolerance."
McCain's name was booed by some members of the audiencewhen Romney mentioned him, but he drew mostly cheers when heappeared before the crowd, many of them McCain supportersbrought in by the campaign.
DRAWS SOME BOOS
He drew boos, however, when he brought up his supportduring last year's Senate debate for a path to citizenship forillegal immigrants. McCain has since said border security mustcome first.
"It is my sincere hope that even if you believe I haveoccasionally erred in my reasoning as a fellow conservative,you will still allow that I have, in many ways important to allof us, maintained the record of a conservative," McCain toldthe conference.
"I am proud to be a conservative," he said.
McCain said he had spoken to Romney, congratulated thegovernor and added they had agreed to sit down together at alater date.
Some attendees said they were disappointed Romney wasleaving, calling him the only conservative candidate in therace.
"This leaves me very concerned about the future of theRepublican Party," said Nathan Shapiro, 22, a college studentin New York. "I don't think McCain will carry on the traditionsof the Republican Party, he's not a real conservative."
Romney said he was pulling out of the race in order to letRepublicans prepare for a general election battle against thetwo remaining Democrats, both whom have campaigned to withdrawU.S. troops from Iraq.
"In this time of war, I simply cannot let my campaign be apart of aiding a surrender to terror," he said.
Romney, 61, had vowed to fight on after Super Tuesday, butthe abrupt reversal followed a meeting with advisers onWednesday. Romney, a former venture capitalist, has spent morethan $35 million (18 million pounds) out of his own pocket tofund his campaign.
"This is not an easy decision for me. I hate to lose," anemotional-looking Romney said.
Many Republicans are eager for an end to the nominatingcontest between McCain, Romney and Huckabee in order to beginwhat is expected to be a difficult fight against either Clintonor Obama.
Romney's decision will raise pressure on Huckabee to do thesame, although he has said he will continue his run fuelled byevangelical Christians.
Romney said he did not want to extend a fight that couldpossibly last until Republicans hold their nominatingconvention in late summer.
"If I fight on in my campaign, all the way to theconvention, I would forestall the launch of a national campaignand make it more likely that Sens. Clinton or Obama would win,"Romney said.
Romney did not endorse McCain in his speech. The two haveengaged in a bitter cross-fire in recent weeks over who is thereal conservative.
(To read more about the U.S. political campaign, visitReuters "Tales from the Trail: 2008" online athttp://blogs.reuters.com/trail08/
(Reporting by Steve Holland, Andy Sullivan, DeborahCharles; Editing by Patricia Wilson and David Wiessler)
