As President Donald Trump on Friday prepared for a second visit to hurricane-ravaged Texas, he found time to rail against former FBI Director James Comey and 2016 Democratic nominee Hillary Clinton on Twitter.

Wow, looks like James Comey exonerated Hillary Clinton long before the investigation was over...and so much more. A rigged system! — Donald J. Trump (@realDonaldTrump) September 1, 2017

Trump has offered a variety of explanations for why he fired Comey in May, from the agency’s probe of his campaign’s Russia ties to Comey’s handling of the Clinton investigation.

Trump’s tweet on Friday seems to be a reaction to new claims that Comey had drafted a statement exonerating Clinton before the investigation was officially over. In a letter sent Wednesday to the current FBI director, Christopher Wray, Sens. Lindsey Graham (R-S.C.) and Chuck Grassley (R-Iowa) claimed that Comey began plans to end the investigation as early as April or May 2016.

The president is expected to travel to Texas on Saturday, where residents are still reeling in the aftermath of Hurricane Harvey, following criticism of his earlier visit to the flood-ravaged region. Trump tweeted after Tuesday’s trip that he had seen storm damage “first hand,” but reporters who had been traveling with him begged to differ.