TRENTON - New Jersey's pugnacious, budget-cutting Gov. Chris Christie - widely mentioned as a potential Republican candidate for president - is catching grief for taking a state helicopter to his son's high-school baseball game.

Critics portrayed Christie as a hypocrite, given his tough talk about runaway spending, and Democrats yesterday called for an investigation.

"Gov. Christie obviously doesn't include himself in his hollow call for shared sacrifice," Democratic state Assemblyman Paul Moriarty said, as he called on the governor to detail publicly his use of State Police helicopters and reimburse the taxpayers for any personal or political trips. "Gov. Christie must learn that taxpayers cannot afford his helicopter joyrides."

"The governor does not reimburse for security and travel," said Christie spokesman Michael Drewniak, who called the use of the helicopter "extremely limited and appropriate."

While State Police helicopters cost $2,500 an hour to operate, State Police Superintendent Rick Fuentes said that giving Christie a lift did not cost taxpayers anything extra because the pilots need to put in flying time anyway to keep their skills sharp.

Paul Loriquet, a spokesman for the New Jersey Attorney General's Office, said that as the state's chief executive, Christie can use the helicopter "at any time for any purpose" and that it is up to the governor to decide if he should reimburse the state for personal use.

Christie, his wife, Mary Pat, and an aide arrived by helicopter just before Tuesday night's game between Delbarton High School and St. Joseph's of Montvale began in Montvale. The couple stepped off the aircraft and into a trooper-driven car that drove them 100 yards to the bleachers, where they watched the game while flanked by state troopers. The Christies left during the fifth inning, and play was stopped briefly while the helicopter took off.

The governor's oldest son, Andrew, attends Delbarton, a Catholic prep school, where he plays catcher.

According to the police, Christie has been aboard State Police helicopters 35 times since taking office a year-and-a-half ago, including flyovers to survey flood and storm damage. State Police and the governor's office did not say which, if any, of the trips were personal or political, or whether the governor has ever reimbursed the state.

A spokesman for the state Republican Party referred all questions to the governor's office.

Christie, a former federal prosecutor who indicted politicians for misusing public money, has become a darling of the GOP, with party loyalists begging him to run for president. Christie left the ballgame to dine at the governor's mansion in Princeton with a delegation of Iowans who tried - unsuccessfully - to persuade him to mount a White House bid.

He has built a national profile by fighting runaway spending by even the smallest state agencies and by calling for shared sacrifice by all public employees. He has issued nearly two dozen vetoes of spending by state authorities - some for less than $1,000.

Christie has faced criticism over other travel-related expenses.

The Justice Department's inspector general found that Christie engaged in a pattern of abuse when he was U.S. attorney by billing taxpayers for stays at luxury hotels. Christie said that he stayed in more expensive hotels only when cheaper ones weren't available.

The use of aircraft at state expense has caused problems for other governors around the country, including former Alaska Gov. Sarah Palin, who repaid about $8,000 for nine state trips she took with her children.