MYRTLE BEACH, S.C. — Jon Huntsman dropped his struggling campaign for the 2012 Republican presidential nomination Monday and endorsed rival Mitt Romney.

The former governor of Utah and ambassador to China bowed to the inevitable, hastening the end of a beleaguered campaign that had little money, next to no popular support and no prospect for significant gains in any states coming up on the primary calendar.

“Today I am suspending my campaign for the presidency,” Huntsman said. “I believe it it is now time for our party to unite around the candidate best equipped to defeat Barack Obama. Despite our differences and the space between us on some if the issues, I believe that candidate is Mitt Romney.”

Romney didn't attend the hastily arranged event.

Huntsman, 51, was joined by his wife, Mary Kaye, his daughters and his father at the Myrtle Beach Convention Center, the site of a GOP candidate debate Monday night. He went out criticizing unnamed rivals and others for the attack ads that have flooded the airwaves in Iowa, New Hampshire and now South Carolina.

“This race has degenerated into an onslaught of negative and personal attacks not worthy of the American people,” he said. “At its core, the Republican Party is a party of ideas, but the current toxic forum of our political discourse does not help our cause. It is just one of the many reasons why the American people have lost trust in their elected leaders.”

A favorite of many editorial pages — The State, South Carolina’s largest newspaper, which McClatchy owns, endorsed him only Sunday — Huntsman long touted his conservative credentials as a tax-cutting governor. But he never caught on with the conservatives who dominate the party, for several reasons.

First, his acceptance of President Barack Obama’s nomination to serve as ambassador to China — along with praise for Obama at the time — made him suspect to zealous anti-Obama conservatives.

Second, his low-key demeanor rendered him all but invisible in the nationally televised debates that have dominated the campaign.

Third, his statement that he believes that human activity contributes to global warming — “I believe in evolution and trust scientists on global warming. Call me crazy." — was out of line with conservative orthodoxy.

Though a fellow Mormon, Huntsman often sparred with Romney. He joined with rivals who called the former governor of Massachusetts a flip-flopper, saying Romney "has been on three sides of every major issue" and that he lacked a “core.” Huntsman skipped the Iowa caucuses, betting everything on New Hampshire, only to come in a distant third behind Romney and U.S. Rep. Ron Paul of Texas.

He bravely called that third-place finish a “ticket to ride” in next-voting South Carolina. But he's in a distant last place in polls here, a state that holds the first-in-the-South primary Saturday.

He's also in last place in Florida polls, a state in which he initially based his campaign in hopes of establishing it as a firewall that would restore his effort should it falter in any of the first three voting states.

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