Most people are careful when they withdraw money from ATMs because it's their money.

But politicians draw on OPM — other people's money — with casual abandon because the rules on candidate expenditures from campaign funds are so vague. It's difficult to tell the difference between a campaign expense, which is legal, and a personal expense, which is not.

Cavalier use of his OPM machine is at the root of 2008 presidential contender John Edwards's trial. Witnesses, including an aide who agreed to pretend Edwards' love child was his, detailed how the candidate leaned on political donors to help hide his mistress.

One of New Jersey's most powerful politicians, Essex County Executive Joseph DiVincenzo, used campaign funds to pay off $250,000 in personal credit-card debt over the past decade. He says they were political expenses, but won't show the details to prove it.

Recently, DiVincenzo charged his campaign $3,000 for a trip with buddies whose names he won't reveal to the luxurious El San Juan Resort & Casino in Puerto Rico. It's hard to tell if this was a personal or campaign expense.

At least South Jersey Congressman Rob Andrews includes his family in the fun when he uses OPM. He charged his campaign for a trip to Scotland for a wedding, and a "fund-raiser" that also celebrated a daughter's graduation.

Clearly, state and federal campaign expense rules have to be tightened. New Jersey's Election Law Enforcement Commission asked the Legislature to fill in the blanks on expense reports. But voters looking for clarity shouldn't hold their breath.

Assembly Speaker Sheila Oliver says she will consider legislation. But considering and committing are very different. Maybe Oliver doesn't want to embarrass her boss. She's an Essex County administrator for DiVincenzo.