But a third is that maybe people just don’t care. Voters haven’t hesitated to elect presidents with financial irregularities in their past before. Rubio is basically following Richard Nixon’s playbook from his famous 1960 “Checkers speech,” in which he dispensed with accusations of financial improprieties by appealing to voters as a man of little means: “We lived rather modestly. For four years we lived in an apartment in Parkfairfax, in Alexandria, Virginia. The rent was $80 a month. And we saved for the time that we could buy a house …. This will surprise you, because it is so little, I suppose, as standards generally go, of people in public life.”

Nor did financial irregularities block Bill Clinton’s path to the White House. He and his wife, Hillary Clinton, whom Rubio would be likely to face if he wins the Republican nomination, faced questions about their financial past as well. There were issues about unpaid taxes on a car, returns on commodity investments, and most famously their investment in Whitewater, a failed real-estate development. Despite these various questions, Clinton was elected and re-elected as president. (That isn’t to say they were harmless: After years of investigation and millions in expenses, inquiries into Watergate failed to produce any evidence of wrongdoing—but the investigation ultimately spiraled into Bill Clinton’s impeachment in the Monica Lewinsky scandal.)

Nixon and the Clintons were able to convince voters that these irregularities were the result not of dishonesty or intentional wrongdoing, but of honest mistakes by people who didn’t come from money. The president’s job isn’t to be accountant-in-chief, and the most business-astute presidents have tended to be mediocre at best in the White House, while failed haberdasher Harry Truman is well regarded. That means questions about Rubio’s finances are perhaps most useful as a litmus test about his probity. Since voters seem to generally find Rubio trustworthy, that’s a battle he’s in a good position to win in the absence of clear evidence of wrongdoing.