President Donald Trump just issued a direct and ominous threat to the Justice Department.

“What are they afraid of? Why so much redacting? Why such unequal ‘justice?’ At some point I will have no choice but to use the powers granted to the Presidency and get involved!” Trump tweeted on Wednesday morning. He even went so far as to call the US justice process “A Rigged System.”

Here’s what he’s referring to: Trump’s GOP congressional allies are upset the DOJ won’t hand over unredacted documents related to ongoing investigations. Basically, law enforcement officials say it’s inappropriate to hand over those materials to Congress while investigations are still in progress. But conservatives in Congress allege the DOJ is a corrupt institution that bungled multiple investigations — not least the one about possible Trump-Russia collusion during the 2016 presidential election — and, therefore, requires stringent oversight.

That, in part, is why Reps. Mark Meadows (R-NC) and Jim Jordan (R-OH) requested the memo Deputy Attorney General Rod Rosenstein wrote where he outlined what special counsel Robert Mueller could investigate. But on Monday, the Justice Department told the Congress members it would not send along that memo.

Trump may have heard of the denied request and threatened to involve himself in the standoff — which could jeopardize the DOJ’s independence to do its job.

A Rigged System - They don’t want to turn over Documents to Congress. What are they afraid of? Why so much redacting? Why such unequal “justice?” At some point I will have no choice but to use the powers granted to the Presidency and get involved! — Donald J. Trump (@realDonaldTrump) May 2, 2018

Trump, however, does have broad authority to declassify any information he wants, which means he could remove redactions from documents and compel the DOJ to hand over those materials to Congress. It would be unusual, though, for a president to do that for documents used in ongoing investigations.

And that’s not all: The president, of course, has the authority to fire personnel. He continues to threaten Rosenstein’s job, and it’s possible he’s using the memo fight to lay the groundwork for the deputy attorney general’s ouster.

On Tuesday, Rosenstein, who oversees the Mueller probe, vowed not to bow to external pressure. “There have been people who have been making threats privately and publicly against me for quite some time,” he said at a “Rule of Law” Day event at the Newseum in Washington, DC. “I think they should understand by now the Department of Justice is not going to be extorted.”

But it’s unclear how the DOJ will react if the president is one of the extorters.