President Donald Trump has confided in those close to him that he’s getting increasingly worried about the possibility of impeachment, according to a Thursday NBC News report.

Trump’s alarm has reportedly grown with the progress of special counsel Robert Mueller’s probe and the looming threat of Democrats taking over the House.

He’s also likely becoming increasingly uneasy due to Republican signaling; this week, Sens. Bill Cassidy (R-LA) and Marco Rubio (R-FL) conveyed their discomfort with Trump’s possible connection to the crimes.

The bulk of the Republican caucus, however, is remaining steadfastly by his side.

Per NBC News, Trump’s worry is poisoning his mood, sending him on a rampage through the White House, lashing out at friends and foes who cross his path.