Republicans seeking to run cover for Donald Trump are using Robert Mueller’s refusal to stray from his report as a weapon to bludgeon his credibility. The president’s allies on the House Judiciary Committee used their allotted time during Wednesday’s hearing to float wild conspiracy theories about his integrity and the Russia probe, suggesting that Mueller is biased against Trump and that his investigation was corrupt. Mueller, his hands tied by his wish not to appear politically-motivated, largely declined to fight back.

Representatives Jim Jordan, Louie Gohmert, and Matt Gaetz are among the Republicans who used Mueller’s reticence to their advantage. Jordan, sporting his signature shirtsleeves, pressed the former special counsel on a conspiracy theory about the origins of the FBI’s probe that suggested Joseph Mifsud, the professor who reportedly told George Papadopoulos that Russia had dirt on Hillary Clinton, was actually sent by the United States government to set up Papadopoulos and justify the probe’s launch. Trump, who has spread numerous conspiracy theories of his own about Mueller’s efforts, appeared to give Jordan a nod of approval, retweeting a video of his monologue with the caption, “Boom…Jim Jordan just blew the lid off the Hoax.”

Mueller, who told lawmakers in his opening statement that there were matters he could not and would not discuss, mostly avoided hitting back at the Ohio Republican, telling him, “I can’t get into it.” He responded similarly to Gohmert, who mostly used his time to shout accusations at the former special counsel, saying that the episodes in which Trump attempted to obstruct justice outlined in the second part of Mueller’s report were merely a justified reaction by the president to an unfair, unlawful investigation. It was not Trump who obstructed justice, Gohmert charged, but Mueller himself. Minutes later, Gaetz used his allotted time to fire off a number of conspiracy theories, including that the dossier prepared by Christopher Steele was based on Russian disinformation. In response, Mueller occasionally told Republicans that he disagreed with their “characterizations” of his work, but largely referred them to his 448-page report. Only after one Republican compared said report to a flaming bag of feces did Mueller offer a stern rebuttal.

“You made a political case,” California Rep. Tom McClintock said during the testy exchange. “You put it in a paper sack, lit it on fire, dropped it on our porch, rang the doorbell, and ran.”

“I don’t think you’ve reviewed a report that is as thorough, as fair, as consistent as the report we have in front of us,” Mueller shot back.

It was about the strongest pushback Mueller allowed himself during his testimony before the House Judiciary Committee, which Democrats had hoped to use to build momentum for possible impeachment proceedings—or at least to hurt Trump in the lead-up to 2020. Though he said early on in his testimony that the president “was not exculpated,” and later that Trump could be tried when he leaves office, Mueller mostly offered clipped responses to Democrats, too. Meanwhile Republicans, who view the testimony as an opportunity to poke holes in the report, exploited Mueller’s relative silence to spout baseless and misleading claims in defense of the president, parroting his theories that the special counsel and former FBI director were “best friends,” for instance, and that therefore the probe wasn’t credible.

Mueller’s legal inability and personal unwillingness to wade into politically fraught waters is understandable; discussing certain matters could jeopardize ongoing work, and allowing himself to be used by either side could further injure the authority of his report, which has already been filtered through the deeply partisan lens of Trump-era politics. But that’s also allowed Republicans to advance their own talking points, virtually unchecked. The hearings were always unlikely to move the needle one way or another. Mueller’s approach, which allowed the GOP to feed talking points to their base, virtually assures that they won’t.

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