In May 2017, President Trump fired FBI Director James Comey. That decision triggered Acting Attorney General Rod Rosenstein's appointment of Robert Mueller as Special Counsel. That investigation would span the bulk of Trump's term. Although Trump was ultimately not indicted, Mueller released a 400-page report that identified a series of what could have been indictable offenses, but for DOJ policy which prohibited the indictment of a sitting President.
Many of the constitutional issues that Mueller grappled with were unsettled when his report was written.Nixon v. Fitzgerald spoke to civil presidential immunity, but the Supreme Court had never addressed presidential criminal immunity. Seven years later, Chief Justice Roberts's majority decision in Trump v. United States has undermined key aspects of Mueller's framework. Indeed, with the benefit of hindsight, I do not even think Rosenstein's decision to appoint Mueller in the first place would have been proper. Firing Comey was a "core" exercise of Article II powers that could not be criminalized by a generally-applicable obstruction statute. I alluded to this point in my post about why the Chief Justice wrote such a sweeping opinion. Here, I will compare and contrast Mueller on Trump, and Roberts on Trump.
First, Chief Justice Roberts explains that the President's exercise of the removal power is a "core" power, which Congress cannot criminalize.
