President Donald Trump and his Republican allies have so far dealt with the impeachment inquiry being led by House Democrats in a familiar way: by attacking the legitimacy of the investigation itself and declaring it to be an unconstitutional sham process. “Your inquiry is constitutionally invalid and a violation of due process,” Counsel to the President Pat Cipollone wrote in a recent letter to Nancy Pelosi and other top Democrats, which declared the Trump administration's refusal to cooperate with the (actually very constitutional) impeachment process. On Thursday, Sen. Lindsey Graham led a group of Republican senators in a resolution condemning the impeachment process, which he believes is “illegitimate, is unconstitutional, and should be dismissed in the Senate without a trial.” But there's one major problem with their aggressive strategy: A federal judge has now legitimized the impeachment inquiry—and forcefully struck down Republicans' main argument against the probe.

In a ruling Friday that grants House Democrats the right to view grand jury testimony gathered by former Special Counsel Robert Mueller—itself a major victory as Democrats consider whether Trump obstructed justice—District Judge Beryl A. Howell officially declared that Democrats are conducting a legitimate impeachment inquiry. While Republicans have argued that the House probe is illegitimate because the full House did not vote on a resolution authorizing it, Howell ruled that no such resolution is needed for an impeachment inquiry to start. “Even in cases of presidential impeachment, a House resolution has never, in fact, been required to begin an impeachment inquiry,” Howell writes in her 75-page opinion, calling the Trump administration's arguments “fatally flawed.” “The precedential support cited for the ‘House resolution’ test is cherry-picked and incomplete, and more significantly, this test has no textual support in the U.S. Constitution, the governing rules of the House, or Rule (e), as interpreted in binding decisions,” Howell writes. (House Democrats have been conflicted on conducting a full vote authorizing impeachment but have so far held off, as it could harm vulnerable Democrats in swing districts.)

Howell, who was appointed by President Barack Obama, also undercuts other arguments the Trump administration put forth for why Democrats shouldn't get their hands on the grand jury material, such as their claim that Democrats hadn't yet exhausted their other options for obtaining the information they're seeking. Noting the Trump administration's very obvious history of stonewalling Democrats, Howell writes in her opinion that the administration's arguments “smack of farce.” “The reality is that DOJ and the White House have been openly stonewalling the House's efforts to get information by subpoena and by agreement, and the White House has flatly stated that the Administration will not cooperate with congressional requests for information,” the judge writes. Howell also takes issue with the Department of Justice's attempt to step on the authority of a co-equal branch of government and the powers that Article I of the U.S. Constitution grants them. “DOJ urges this Court to second-guess a co-equal branch of government and find that the steps taken by the House fall short of showing a primary purpose of undertaking an impeachment inquiry,” Howell writes. “In so doing, DOJ again invites an impermissible intrusion on the House's constitutional authority under the Rulemaking and Impeachment Clauses.”

The ruling and its validation of the impeachment process comes as Republicans have upped their tactics to very publicly oppose the impeachment inquiry, from Graham's Senate resolution to the recent attempt by House Republicans to storm the secure room where closed-door impeachment hearings are being held, rules and national security be damned. Howell's ruling and its clear rebuke of one of their biggest arguments clearly gives Republicans even less of a leg to stand on in their opposition to the constitutional process, and how they'll choose to move forward remains to be seen. But gaining official legitimacy in the eyes of the courts is sure to be a big boon for Democrats as they continue to subpoena materials and witnesses in their impeachment investigation—and now do so with key Mueller evidence in hand. “The court's thoughtful ruling recognizes that our impeachment inquiry fully comports with the Constitution and thoroughly rejects the spurious White House claims to the contrary,” House Judiciary Committee Chairman Jerrold Nadler said in a statement Friday. “This grand jury information that the Administration has tried to block the House from seeing will be critical to our work.”

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