The Justice Department did not return requests for comment.

Read: Rod Rosenstein will decide the outcome of Mueller’s investigation

Corey Lewandowski, Trump’s former campaign manager, who remains a close confidant, said he believes Mueller left the obstruction question up to Rosenstein on purpose. “He couldn’t make the decision, so he turned it over to his boss, Rod Rosenstein,” Lewandowski said. He added that while Rosenstein is “no fan” of Trump, he’s also not a “hack.” “He’s the one who ultimately made the decision, in consultation with Barr, that there was no obstruction based on the evidence they were given from Mueller,” he said.

Mark Corallo, who served as the Trump legal team’s spokesman until July 2017, said he believes Rosenstein’s involvement in deciding whether or not Trump obstructed justice only “strengthened the conclusion” reached by Barr. “This guy is a career prosecutor, highly regarded, follow-the-facts public servant,” said Corallo, who served as public-affairs director at the Justice Department under former President George W. Bush.

And Rudy Giuliani, one of Trump’s lead outside lawyers, told The Atlantic that Rosenstein’s role should ease any suspicions that political lackeys gave Trump a favorable ruling. After appointing Mueller, Rosenstein gave the special counsel ample freedom to conduct a tough investigation, Giuliani said. Rosenstein was “supervising the investigation,” Giuliani said. “He could have stopped all those things. He didn’t. He let Mueller do everything Mueller wanted to do to get an answer, if it was there, that might be unfavorable.”

He added: “For the doubters, the fact that Rosenstein agrees with it [the conclusion that Trump did not obstruct justice] makes it that much more acceptable to people who want to criticize.”

Rosenstein’s tumultuous tenure as deputy attorney general has been punctuated by attacks from the president—who has called him “weak”—and spats with GOP lawmakers. House Freedom Caucus Chairman Mark Meadows went so far as to file articles of impeachment against Rosenstein last summer. After then–Attorney General Jeff Sessions recused himself from the Russia probe in early 2017, Rosenstein became the one person capable of firing Mueller directly. However, far from entertaining Trump’s characterization of the Mueller probe as a “witch hunt,” Rosenstein quietly defended the special counsel and pushed back on some requests from Trump’s allies in Congress for sensitive, Russia-related documents.

Even so, Rosenstein’s role in clearing Trump of obstruction has raised eyebrows among some legal experts, given his involvement in Comey’s dismissal in 2017. Mueller reportedly investigated that episode as a possible effort by Trump to derail the Russia probe, which Comey was in charge of at the time. According to both The New York Times and a recently released memoir by McCabe, Trump drafted a letter before firing Comey that outlined why he wanted him gone, and mentioned the Russia investigation. Rosenstein saw Trump’s letter during a meeting in the Oval Office, but then wrote a separate memo for the president about why Comey should be fired that centered on his handling of the Hillary Clinton email investigation. Trump ultimately used the Rosenstein memo to justify Comey’s firing, despite later telling NBC that he fired Comey over “this Russia thing.”