HARRISBURG, Pa. -

Pennsylvania's primary elections were marked by spotty reports of low turnout Tuesday, no surprise given the remnant of a winter storm in the west and the lack of drama in the presidential nominating campaigns.

Former Massachusetts Gov. Mitt Romney has had no serious opposition for the GOP presidential nomination since former U.S. Sen. Rick Santorum, R-Pa., dropped out two weeks ago.

President Barack Obama is unopposed for the Democratic nod — a far cry from four years ago when his race against Hillary Rodham Clinton riveted the state for weeks.

In the Lancaster County town of Gap, Robert Arters said he cast his ballot for Romney, and would do so again in the fall.

"I think Romney is the better of the two because I think he, being a business manager, he knows how to get economies in control," Arters said. "He knows how to economize on things. And I believe he'll be able to handle that quite well."

Arguably the hottest statewide race is the two-way battle for the Democratic nomination for attorney general between Kathleen Kane, a former Lackawanna County prosecutor, and former U.S. Rep. Patrick Murphy of Bucks County. The winner will take on Republican David Freed, the Cumberland County district attorney, in November.

The primary represented the first test for the state's new voter identification mandate, although the photo IDs will not be required until November.

Secretary of State Carol Aichele, who visited some polling places in Philadelphia, concluded the new law seemed to be working well, and her office reported no complaints from county elections officials about the voter ID implementation.

Five men are competing for the Republican nomination to challenge Democratic U.S. Sen. Bob Casey's re-election bid: Steve Welch, a Chester County entrepreneur who is endorsed by the state GOP; Tom Smith, a wealthy former coal company owner from Armstrong County; ex-Pa. Rep. Sam Rohrer of Berks County; suburban Harrisburg lawyer Marc Scaringi; and David Christian of Bucks County.

In another row-office contest, for the Republican nod for state auditor general, Pa. Rep. John Maher of Allegheny County is competing against former banking lobbyist Frank Pinto.

Among the congressional primaries, several races stand out, including the 17th District race. Ten-term Democratic Rep. Tim Holden faces a stiff intraparty challenge from Matthew Cartwright, a personal injury lawyer.

In the state Legislature, only four incumbent senators, out of 25 districts open this cycle, have primary opponents, while in the House only 28 incumbents could be defeated Tuesday.

Also on Tuesday, voters will fill six vacant state House seats in special elections concerning one district each in Allegheny, Lehigh and Montgomery counties, and three in Philadelphia.