BOSTON – Republican campaign dropout Mitt Romney endorsed John McCain for the party’s presidential nomination and asked his national convention delegates to swing behind the likely nominee.

“Even when the contest was close and our disagreements were debated, the caliber of the man was apparent,” the former Massachusetts governor said, standing alongside his one-time rival at his now-defunct campaign’s headquarters. “This is a man capable of leading our country at a dangerous hour.”

“Primaries are tough,” said McCain, referring to their earlier rancor. “We know it was a hard campaign and now we move forward, we move forward together for the good of our party and the nation.”

The two met privately before appearing together at a news conference. McCain had campaigned in Vermont and Rhode Island but added a flight to Boston to accept the endorsement.

McCain effectively sealed the nomination last week when Romney withdrew from the race; only former Arkansas Gov. Mike Huckabee and libertarian-leaning Texas Rep. Ron Paul remain. But neither has a chance to catch McCain in the convention delegate hunt.

In early primaries and caucuses, Romney collected 280 delegates. The number is enough to move McCain close to the total of 1,191 needed to clinch the nomination a full nine months before the November general election.

Huckabee was not ready to bow out.

“Right now there’s a great big ‘me, too’ crowd coming together (for McCain),” Huckabee said in LaCrosse, Wis. “There’s a lot of folks, sort of, in the establishment of the party that is not now wanting to be left out.” He added, “I’m just not willing to be part of the coronation yet.”

Romney’s nod of support capped a bitter yearlong rivalry between the two men over the party’s nomination. Romney criticized McCain in television ads in New Hampshire, and both candidates mixed it up almost daily during campaign events and debates. Neither is especially fond of the other.

Associated Press writers Mike Glover in Iowa, Todd Richmond in LaCrosse, Wis., and Deanna Martin in Indiana contributed to this report