Probably for as long as there have been campaign accounts, there have been politicians tempted to dip into them for their own use. Lately, this particular type of greed has been getting people into trouble.

In October, New Mexico Secretary of State Dianna Duran resigned and pleaded guilty to charges stemming from her habit of siphoning thousands from her campaign fund to underwrite her gambling addiction. She was later sentenced to 30 days in jail on top of being ordered to pay fines, complete community service and write a public apology. In South Carolina, an investigation by the Center for Public Integrity and the Charleston Post and Courier found that state politicians had spent an eye-popping $100 million since 2009 on dubious personal expenses, including payments to their own businesses and for spousal artwork.

That investigation, among others, spun off from the conviction of former state House Speaker Bobby Harrell last year for misusing campaign funds. Earlier this year, former state Sen. Robert Ford received a suspended sentence for turning his campaign treasury into his own ATM, spending money on items such as car payments, a gym membership and male enhancement pills.

This may seem like small stuff at a time when billionaires are routinely writing seven-figure political checks. And to some extent, campaign donors already know their money is going to be devoted to the candidate’s betterment. They may not care that their money is paying for GoPro cameras or camping equipment -- actual examples from South Carolina -- rather than yard signs or robocalls.

But from a policy standpoint, it’s better to keep politicians from walking off with the dough. Otherwise, we’re talking about bribes. “The reason we limit campaign contributions is we worry that people are going to use them to get favors from government,” says Daniel Weiner, senior counsel at the Brennan Center for Justice. “Obviously, that risk increases when politicians can use that money to buy the things they want.”

Of course, innocent mistakes are often made, and it’s human nature to cut corners in one’s own favor. There’s no field of endeavor, after all, where people don’t cheat a little when it comes to things like claiming mileage reimbursement. That’s why most states, as well as the federal government, seek to offer clarity by walling off certain expenses as inherently personal and not to be paid for out of campaign funds, such as mortgages and medical bills.

If it’s something you’d have to pay for even if you weren’t an officeholder or candidate, you’re not supposed to use money out of the campaign kitty. But sometimes that gets into gray areas, especially when it comes to things like travel. There may well be a legitimate reason for a trip. On the other hand, a legislator might just have tacked on a meeting to justify getting a free ride.

It certainly looks bad when a politician gets caught. That doesn’t always happen, though. Ethics enforcement is not always a top priority -- especially in places like South Carolina where lawmakers are left to police themselves. Not all states, in fact, forbid personal use of campaign funds. Virginia Gov. Terry McAuliffe convened an “integrity commission” following the conviction of his predecessor, Robert McDonnell, on corruption charges. In October, the panel recommended that the state impose a new ban on personal use of campaign dollars.

One of its other recommendations was a big raise for state lawmakers. Part-time legislators, in particular, can easily feel undercompensated. That’s one reason why it’s so tempting for them to dip into the office or campaign accounts. “Most people aren’t setting out to commit fraud,” Weiner says, “but if there’s a vague standard and you’re feeling strapped for cash, then the temptation is there.”

*This story has been updated to reflect developments in Dianna Duran's case.