Romney campaign takes off

GOP race shifts to South

COLUMBIA, S.C. - Mitt Romney swept into South Carolina on Wednesday in pursuit of a confirming victory in the race for the Republican presidential nomination, buoyed by a second straight electoral triumph, bulging campaign coffers and warm words from the state's pre-eminent practitioner of tea party politics.

"I don't want to be overconfident," said the Republican front-runner. But increasingly, he was talking about his plans for challenging President Barack Obama in the fall, not his primary foes of the moment.

Running out of time, his GOP rivals showed no sign of surrender.

Newt Gingrich welcomed Romney into the first Southern primary state with a fresh attack on his business career and a new television ad painting him as a flip-flopper on abortion. Said former Pennsylvania Sen. Rick Santorum: "South Carolina is going to be different. It is wide open for anyone."

Texas Gov. Rick Perry drawled his way through a busy campaign day, displaying a Southern attribute that Romney, the former Massachusetts governor, could not hope to match.

Wealth gap increasing

WASHINGTON - Tensions between the rich and poor are increasing and at their most intense level in nearly a quarter-century, a new survey shows. Americans now see more social conflict over wealth inequality than over the hot-button topics of immigration, race relations and age.

The survey released Wednesday by the Pew Research Center highlights U.S. perceptions of the economic divide, an issue that has moved to the forefront in the 2012 presidential campaign amid stubbornly high unemployment, increasing poverty and protests by the Occupy movement.

The findings come as voters in New Hampshire's primary Tuesday night made clear that the economy was the issue that mattered most to them. In the end, they chose Mitt Romney by a large margin, even as Republican rivals already gearing up for more competitive contests in South Carolina and elsewhere had stepped up populist attacks on him as a heartless corporate raider who slashed jobs.

President Barack Obama has been promoting a campaign message of middle-class opportunity, calling for higher taxes on the very rich and successfully pushing a two-month extension of a payroll tax cut.

The Pew survey shows that younger adults, Democrats and African-Americans remained the most likely as in previous years to cite the existence of strong disagreements between rich and poor. But in the last two years, three important swing groups - whites, middle-income Americans and political independents - registered some of the biggest increases in those who now also hold this view.

Marines probing battlefield video

WASHINGTON - The Marine Corps said Wednesday it is investigating a video depicting what appears to be four Marines urinating on the corpses of Taliban fighters.

In a statement, the Marine Corps said it has not verified the origin or authenticity of the YouTube video. But it also said the actions portrayed are not consistent with Marine values.

If verified the video could create a strong backlash in the Muslim world and beyond for the disrespectful actions it portrays.

The case is being referred to the Naval Criminal Investigative Service, the Navy's worldwide law enforcement organization, said NCIS spokesman Ed Buice.

The Council on Islamic-American Relations, a prominent Muslim civil rights and advocacy group based in Washington, quickly condemned the video.

Blast kills Iranian official

TEHRAN, Iran - It seemed a clockwork killing: Motorcycle riders flashed by and attached a magnetic bomb onto a car carrying a nuclear scientist working at Iran's main uranium enrichment facility. By the time the blast tore apart the silver Peugeot, the bike was blocks away, weaving through Tehran traffic after what Iran calls the latest strike in an escalating covert war.

The attack - which instantly killed the scientist and fatally wounded his driver on Wednesday - was at least the fourth targeted hit against a member of Iran's nuclear brain trust in two years. Tehran quickly blamed Israeli-linked agents backed by the U.S. and Britain.

Secretary of State Hillary Rodham Clinton denied any U.S. role in the slaying, and the Obama administration condemned the attack. However, provocative hints from Jerusalem reinforced the perception of an organized and clandestine campaign to set back Iran's nuclear ambitions.

The day before the attack, Israeli military chief Lt. Gen. Benny Gantz was quoted as telling a parliamentary panel that 2012 would be a "critical year" for Iran - in part because of "things that happen to it unnaturally."

The blast killed Mostafa Ahmadi Roshan, a chemistry expert and a director of the Natanz uranium enrichment facility, the centerpiece of Iran's expanding program to make nuclear fuel. Roshan, 32, had planned to attend a memorial later Wednesday for another nuclear researcher who was killed in a similar pinpoint blast two years ago, Iranian media said.

Van der Sloot pleads guilty

LIMA, Peru - After Joran van der Sloot pleaded guilty Wednesday to the 2010 murder of a Peruvian woman he met at a Lima casino, his lawyer argued that the killing was tragically triggered by fallout from the very event that originally brought his client notoriety.

The "persecution" suffered by Van der Sloot after the unsolved disappearance of U.S. teenager Natalee Holloway five years earlier scarred him psychologically with a kind of post-traumatic stress disorder, defense attorney Jose Jimenez told the three female judges who are to sentence his client Friday.

The young Dutchman has been the prime suspect in the Holloway case since she disappeared on Aruba five years to the day before the killing of the 21-year-old Peruvian woman, business student Stephany Flores.

With the evidence against him in the Peru killing strong, Van der Sloot entered a guilty plea Wednesday at his lawyer's urging, hoping for a reduced sentence.

"I truly am sorry for this act. I feel very bad," the 24-year-old defendant said, showing no emotion in a brief admission of guilt in fractured Spanish. He did not use the Dutch translator provided for the proceeding.

- The Associated Press