When Donald Trump was elected, reporters and editors all over sat down to think through the possible reporting tracks on the Trump presidency: There was his new populist movement, his personality and family, his policy plans.

And then there was the corruption beat: Trump had a long history of enriching himself at taxpayers’ expense, and he and his circle did not come out of a tradition that knew the meaning of the term public service.

But a year ago, there was no reporting to do on the corruption story for a simple reason: The Trump administration hadn’t been around long enough.

Well, now it’s been around long enough.

And in recent weeks there has been an escalating series of stories about self-dealing, money flowing to cronies, and high-stakes policy decisions impossibly tangled with personal wealth. What Trump and his critics appear not to have realized is that this — not conspiracies, porn actresses, or divisive comments — is the starkest threat to his presidency.

That’s because Trump ran as a promiscuous, divisive friend of Vladimir Putin. He didn’t run as a crook.

And the politics of corruption are simple: Voters hate it. Trump knows that, and his talk of “the swamp” was about corruption. Attacks on Clinton’s speeches and on her family foundation were damaging (and often dishonest) shorthand for the reality that the Clintons had used their government connections and accomplishments to get rich.

Some of the corruption allegations against Trump are utterly direct. The White House and Secret Service have become huge customers of Trump resorts. Every foreign government, trade association, and interest group with a few bucks to spare spends them at the Trump International down the street from the White House.

More money is flowing out of political slush funds — which is to say, a way for donors to do personal favors for the president’s friends. Melania’s old friend got a $26 million contract. Keith Schiller, Trump’s bodyguard and confidant, is pulling in $15,000 a month.

Discarding the typical rules of propriety has trickled down to the cabinet, whose members have been spending lavishly on private travel, office furniture, tennis tickets, and other forms of government spending more often associated with senior officials in Azerbaijan than the United States.

But the largest sums are deeply entangled with high-stakes policy decisions. Carl Icahn sold his interests in companies that buy steel just before the tariff decision came down. Jared Kushner talked to his Saudi friends about waging economic and actual war on Qatar just after a Qatari loan to his company fell through. (All parties have denied wrongdoing, and there’s no evidence of explicit coordination.)

The broader setting for all of this is a family real estate business that raises, as Thomas Frank recently documented, one giant red flag; a set of global partnerships in which more than a quarter of his partners “have been investigated, charged, or convicted of crimes,” as John Templon wrote; and a Mar-a-Lago milieu that puts the president at close proximity to, as Tarini Parti discovered, a convicted con artist.

It’s worth pausing at this point to note that the definition of official corruption is extremely narrow. John Roberts wrote for a unanimous Supreme Court in 2015 that “tawdry tales of Ferraris, Rolexes, and ball gowns” weren’t enough to send Virginia Gov. Bob McDonnell to jail for taking favors from a donor. The same ruling helped get Sen. Bob Menendez off the hook for taking lavish favors from another donor. The new definition of corruption requires proof of a direct transaction: In exchange for something valuable, a politician performed one of a narrowly defined set of "official acts."

But Roberts also wrote of McDonnell: “There is no doubt that this case is distasteful.”

That is another way of saying that what we typically call corruption isn’t a criminal matter. It’s a political one.

This is an axiom of politics: You can get away with horrible policy, bad leadership, and complicated conflicts of interest. But when you’re caught doing something easier to explain — sexually harassing staffers or stealing even modest amounts of money — you’re announcing your resignation.

Former Rep. Aaron Schock, for instance, is still fighting corruption charges — but his Downton Abbey–styled office made the appearance of corruption too easy to fight. Former Rep. Jesse Jackson Jr. blew campaign funds on a Rolex, fur coats, and Bruce Lee memorabilia, and went to jail without even stealing any public funds. And while former secretary Tom Price dodged concerns about insider trading that could have been worth millions of dollars, expensive plane travel — mere thousands! — ended his career.

(This is a source of some frustration to anti-reform old-timers and radicals on all sides, who think voters ought to care more about policy than a few thousand bucks here and there. And it’s perhaps notable that there are some emphatically nonreform Democrats, Andrew Cuomo and Bill de Blasio, poking their heads out of New York this presidential cycle.)

Anyway: Try explaining the Russia investigation to, well, anyone. Try persuading someone who voted for Trump because of his immigration stance that he and his president are racists. Try complaining about the damage being done to institutions.

Or try telling the story about how the president and his cronies are getting rich from politics.

And the corruption charge, always dangerous politically, may be particularly damaging for Trump. The governing rule of modern politics is that leaders are often more vulnerable on their strengths than their weaknesses. Democrats totally failed to tear down the gilded television image of Donald Trump, successful businessman and tycoon, in their 2016 efforts to explain to voters that he’d actually been just mediocre at business.

But corruption doesn’t contradict what Trump’s fans know about him. It’s just the worst version of what his admirers already think. You can imagine the star of The Apprentice grabbing a little extra for himself and his friends. Corruption is in his character. And while it lacks the glamour or world-historical weight of the rest of the Case Against Trump, it is the theme most likely to swallow his administration. ●