It wasn’t the stress of federal stimulus money that prompted South Carolina Governor Mark Sanford to fly off to Argentina. Today, Sanford held a press conference to tell the world the real reason: he’s been having an affair.

Sanford originally said he “wanted to do something exotic” to unwind after losing a battle with his state legislature and the courts over the federal stimulus package. Sanford refused to take the money, until the courts finally forced him to. Here’s what he argued in a March Wall Street Journal column:

When you’re in a hole, the first order of business is stop digging. South Carolina is in a hole, and it’s not a shallow one. Spending stimulus money on ongoing programs would mean 10% of our entire state budget would be paid for with one-time federal funds — the largest recorded level in state history.

At least Sanford has decided to follow his own advice and stop digging. He called a press conference today and admitted he’s been seeing a woman in South America for several months.

As if he was begging for the news headlines to quote Evita, Sanford said he’s spent the last five days crying in Argentina.

Sanford was considered a potential 2012 presidential candidate. I’d say that’s out the window. He’s resigning as head of the Republican Governors Association.