On the campaign trail: Feb. 16

(AP) - A snapshot of what's happening on the campaign trail on Thursday, Feb. 16, 2012.

Romney struggling to attract white working class

Republican Mitt Romney is faltering with white working-class voters crucial to his party's drive to capture the White House, even as he tries to fend off a rising GOP challenger, Rick Santorum, who wields strong blue-collar appeal.

The wealthy former Bain Capital chief has led his rivals by comfortable margins among white college graduates, according to combined polls of voters in the first five states that held presidential nominating contests. But the exit and entry surveys showed only a modest Romney advantage among whites who lack college degrees, the yardstick analysts typically use to define the working class.

The imbalance was most pronounced among less-educated white men, with whom his lead disappeared.

Santorum's tax returns show rise in wealth

Republican presidential candidate Rick Santorum released four years of federal income tax returns on Wednesday night, showing a sharp rise in his personal wealth spurred by his growing work as Washington-based corporate consultant and media commentator.

Santorum, 53, has sold himself in the Republican primaries as both a social conservative and a Washington outsider, stressing his family's coal-mining background and his appeal to religious and working-class voters. His personal finances tell a different story, detailing the trajectory of a politician who grew more prosperous in the Senate and became a millionaire afterward, at times capitalizing on his Beltway connections.

The former Pennsylvania senator's tax returns show that his annual income surged from nearly $660,000 in 2007 to $1.1 million in 2009 before slipping to $923,000 in 2010.