Tom Brenner / Reuters

Legally, the passage of a House resolution on the impeachment inquiry on Thursday doesn’t mean much. Democrats have already launched the inquiry, and a federal judge ruled last week that they didn’t need to have a vote.

But it’s not clear that the resolution had much political effect either. The final vote on the resolution was 232–196, almost precisely along partisan lines. The story of the impeachment drama inside Washington politics is one of implacable partisanship. The American people have proved somewhat open-minded—as new evidence has emerged, support for impeachment has increased—and a parade of civil servants has spoken out. But among partisan officials, from the White House to Capitol Hill, there’s been barely a defection.

Democrats have coalesced almost uniformly around the inquiry, while Republicans have arrayed themselves even more uniformly against it. The few Republicans willing to voice tentative support are those with nothing politically at stake, such as Representative Francis Rooney of Florida, who announced his retirement as he criticized the president’s behavior.

Thursday’s vote to establish procedures for the inquiry demonstrates this. Every Democrat save two voted for the resolution. They were joined by Representative Justin Amash of Michigan, a conservative libertarian drummed out of the GOP for his criticism of Trump earlier this year. Every Republican voted against it. (Four members, three Republicans and one Democrat, did not vote.)

The witnesses who have already spoken to House investigators show the divide even more sharply. The testimony has been extremely damning, as I have written: The question at this point is not whether Trump acted inappropriately, or whether he was involved, but whether it was bad enough to impeach.

Those witnesses have been a mix of career civil servants and political appointees. One after another, the civil servants have spoken out about how shocked and appalled they were by Trump’s attempts to extract quid pro quos from Ukraine’s president, to get him to intervene in American elections, and to hold up military aid appropriated by Congress. This includes Bill Taylor, who was appointed by Secretary of State Mike Pompeo but who spent his career in the Foreign Service, and Fiona Hill, who was appointed to Trump’s National Security Council but who was never ideologically or personally close to him.

The political appointees who have testified, especially Ambassador Gordon Sondland, have told a substantially similar story. Democrats have questioned Sondland’s testimony and suggested he may have perjured himself, but the account he offered was damaging to the president, showing the ways Trump’s lawyer Rudy Giuliani meddled in Ukraine policy and the president solicited aid—even if the president insisted it not be called a quid pro quo.

Yet no Trump insider has shown any kind of public moral revulsion at Trump’s actions. Consider John Bolton, the former national security adviser. Bolton, by all accounts offered so far, was appalled by the administration’s behavior toward Ukraine. “I am not part of whatever drug deal Sondland and [Mick] Mulvaney are cooking up,” Bolton said, according to Hill. (It’s now apparent that Trump was deeply involved in the drug deal, too.)

But Bolton hasn’t so far been willing to publicly air his revulsion. On Wednesday, House Democrats called Bolton to testify. His lawyer announced that Bolton wouldn’t voluntarily testify; it’s not clear how he’d respond to a subpoena either, and his former deputy Charles Kupperman, who shares the same lawyer, has gone to court to seek guidance on whether he must appear.

This is a microcosm of the Republican response to the impeachment inquiry: There are some who are privately appalled by Trump’s behavior, but they do not apparently feel any moral call to speak out publicly. The same goes for Republican senators, who are willing to give melodramatic quotes anonymously, but are keeping their public remarks buttoned-up. (Bill Kristol insists Republican House members are keeping their powder dry for impeachment, a claim that seems to fit with his past record of predictions.)

That’s very different from the Watergate hearings. By the time the House voted to open an impeachment inquiry against President Richard Nixon, former White House insiders such as John Dean and Alexander Butterfield had already spoken to investigators and blown the whistle on Nixon. Dean’s motives and record may not have been entirely pure—Nixon fired him, and he later pleaded guilty to obstruction of justice—but the fact that a close Nixon loyalist was willing to air the concerns of a “cancer on the presidency” that he had already shared internally was important to the legitimacy of the investigation.

No analogous figure has emerged so far in this process. During debate ahead of the vote, Republican members of the House quoted Alexander Hamilton to argue that any impeachment must be bipartisan. The argument is clever but disingenuous; GOP members know they can simply withhold support for any impeachment proceeding, no matter the evidence, and then declare it illegitimate because they have stonewalled it.

But the party-line split is a problem for Democrats nonetheless. There’s little prospect for mass House GOP defections, and Thursday’s vote suggests Trump’s firewall in the Senate may remain impregnable. But an impeachment that draws no Republican support at all—no matter how consistent the testimony is, and no matter how obvious Trump’s bad behavior is—is by definition partisan. An impeachment inquiry is a deadly serious moment, and proceeding without any Republican backing will likely undermine the inquiry’s legitimacy in the public eye. A purely Democratic impeachment would be a huge risk—but given the president’s abuse of power, the only greater risk would be flinching from holding him to account at all.

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