President Donald Trump escalated his rhetorical attacks on special counsel Robert Mueller’s investigation yet again in tweets Wednesday morning — the day after his former campaign chair Paul Manafort’s trial began and as investigators continue to scrutinize his close associates.

“This is a terrible situation and Attorney General Jeff Sessions should stop this Rigged Witch Hunt right now, before it continues to stain our country any further,” the president tweeted.

Trump has repeatedly complained about the investigation and attacked Mueller publicly, but the public statement that Sessions “should” shut down the probe “right now” is new. (Sessions recused himself from any involvement in the probe last year — but Trump has reportedly urged him privately to reverse that recusal, to no avail.)

..This is a terrible situation and Attorney General Jeff Sessions should stop this Rigged Witch Hunt right now, before it continues to stain our country any further. Bob Mueller is totally conflicted, and his 17 Angry Democrats that are doing his dirty work are a disgrace to USA! — Donald J. Trump (@realDonaldTrump) August 1, 2018

The Russia probe has appeared increasingly dangerous to Trump and his inner circle of late. Manafort is facing two trials, including the one that started Tuesday, that could send him to prison for life. Trump’s former lawyer Michael Cohen is signaling willingness to cooperate with prosecutors, including claiming that Trump knew about his son Don Jr.’s infamous Russian meeting. Trump’s longtime adviser Roger Stone has been in investigators’ crosshairs, too. Thirty-two people, in total, have already been charged. So Trump’s new agitation should come as no surprise.

The real question is whether Trump will take any action to back up his words. For 14 months since the uproar over his firing of FBI Director James Comey — an uproar that prompted Mueller’s appointment — a sort of equilibrium has held. Trump has trashed Mueller’s investigation publicly, but top Justice Department officials involved have generally ignored his statements and resisted interfering with Mueller.

Trump could disrupt this equilibrium at any moment, by firing Sessions or Deputy Attorney General Rod Rosenstein (who actually oversees the probe) or by trying to fire Mueller. Yet so far, he has been hesitant to do so, evidently out of fear of causing another political crisis for himself. Unless the president affirmatively acts to interfere, it seems, the Mueller investigation will continue.

Meanwhile, part of the Mueller probe has focused on whether Trump has attempted to obstruct justice since he’s been in office by trying to impede investigations of himself or his associates. This investigation reportedly focuses on Trump’s use of Twitter (as one of many other topics). So the special counsel’s team will surely view this new tweet with interest.