Walter Shaub late Thursday said “we’re in the heads-on-pikes phase of burgeoning authoritarianism” following the GOP-controlled Senate’s vote to acquit President Donald Trump on impeachment charges.

The former head of the U.S. Office of Government Ethics tweeted a list of the moves that Trump and his allies are now making, and the people they are attacking, such as Sen. Mitt Romney (R-Utah), the lone Senate Republican who voted to convict the president over the Ukraine scandal.

Shaub warned: “This is just the start.”