Anyone who aims to understand our political moment needs to account for the remarkable fact that on the day before he was scheduled to become only the third president in American history to be impeached by the House of Representatives, President Trump hit his highest level of aggregate approval in 33 months.

Yes, that level of approval in the polls — 43.5 percent — is quite low by historic standards. But Trump's polling has been marked by two tendencies almost from the beginning of his presidency: His support has been quite low, but it has also been incredibly consistent. He floated between 36 and 38 percent approval for most of his first year in office. Ever since, he's bounced around in the narrow range between 39 and 42 percent. But on December 17, 2019, as the House prepared to vote on two articles of impeachment, Trump broke out of that rut to hit his highest peak in a very long while.

It wasn't supposed to be like this. Over and over those favoring impeachment have told us to remember 1974. Nixon maintained strong support from Republicans in Congress, conservative intellectuals, and voters in the country at large all through 1973 and most of the first half of the following year, as revelations from the Watergate investigation piled up and the president became implicated in ever-greater acts of wrongdoing. Finally, in the late spring and summer, it all began to crumble, with support for impeachment and removal building fast. The same was bound happen with Trump. All Democrats needed do is present the evidence in gripping public hearings and wait for the implosion.

But it hasn't happened. How come?

Some will point to polarization and the fact that the country is far more deeply divided than it was 45 years ago. That's certainly true, but it doesn't tell us much. Everything that takes place right now unfolds in a polarized context. Why would Trump come through weeks of public testimony with his approval not just holding steady among fervently loyal Trump supporters but actually surging to its highest level since March 2017? Polarization alone can't explain why the president appears to be gaining strength as Democrats make their most concerted case for removing him from office.

What does explain it is a constellation of mutually reinforcing facts and developments over the last few weeks.

For one thing, the economy is continuing to grow solidly instead of slipping into the recession that seemed to be lurking in the shadows a few months ago. For another, Labour leader Jeremy Corbyn got clobbered in the U.K. election, giving a serious morale boost to American conservatives who may have been contemplating drifting away from an unappealing president as he prepares to head into a difficult re-election contest.

Then there's the case that Democrats have made against Trump, which has been less compelling than many expected when the Ukraine revelations first broke wide open in late September. My first thought upon reading the rough transcript of Trump's call with President Volodymyr Zelensky was that Trump was clearly attempting to use foreign aid to extort his Ukrainian counterpart into digging up dirt on Trump's domestic political rival in order to give him an advantage in the 2020 election. That seemed like a self-evident abuse of power.

But then why did hearings in the House spend so much time focusing on what is clearly a policy dispute between the president and the career civil service? Congressional Democrats, the intelligence community, and leading members of Washington's permanent bureaucracy (including its diplomatic corps) have been obsessed to the point of borderline derangement with Russia ever since the 2016 election. Many of these people find the president's solicitude toward Russian President Vladimir Putin, as well as his lack of enthusiasm for supporting Ukraine in its multipronged struggles with Moscow, thoroughly unacceptable.

That's certainly a legitimate view — but it's a disagreement with the White House over foreign policy. And presidents should not be threatened with impeachment and removal from office over policy disputes. The place for policy disputes is the political arena, where voters get to listen to competing sides and then make a decision at the ballot box about which should prevail. By allowing hearings devoted to impeachment to drift repeatedly in the direction of policy conflicts, Democrats ended up making it look like they were out to punish Trump for daring to disagree with them over how to handle Russia and Ukraine. I suspect that has inspired some voters to dismiss the worst accusations against the president.

Finally, there are two utterly damning stories that have appeared over the past week: first, the inspector general's scathing report on the alarmingly unprofessional conduct of the FBI's Russia investigation, and The Washington Post's "Afghanistan Papers," on the mountain of lies that have been told by three administrations about the prospects for success in what is now easily the longest war in American history.

It's impossible to know precisely how much either or both of these stories have influenced public opinion in recent days. What is clear is that both stories severely undermine any effort to portray the American political establishment — and especially the centrist, bipartisan, "permanent Washington" establishment that has been gunning for Trump in the impeachment hearings — as admirable or trustworthy. Together, the IG report and the Post's "secret history" of the war in Afghanistan portray this establishment as sloppy, ignorant, mendacious, and prone to endorse and act on conspiracies that validate its unexamined biases.

Reading either or both of these reports, or just listening to coverage of the basic findings of each investigation, leaves one with the unmistakable impression that America's political leadership is deeply, pervasively corrupt. That certainly doesn't exonerate Trump of his own flagrant acts of corruption. But it does force us to assess the relative gravity of his transgression. Yes, it's very bad that the president acted like a two-bit mob boss trying to shake down a vulnerable member of the democratic neighborhood. But is it categorically worse than administrations of both parties lying to the American people about a war for close to two decades? Or secret courts approving surveillance warrants on the basis of uncorroborated, politically motivated nonsense?

Why is the president riding (relatively) high in the polls as the House prepares to impeach him? Maybe because a significant portion of the country has come to doubt that anyone in the nation's capital has the requisite moral stature to stand in judgment of anyone else's misconduct.

Even Donald Trump's.

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