It turns out that retaliating against witnesses is a crime.

The lawyer who represented Richard Nixon after he left the White House, William Jeffress, says Trump retaliatory action against Don McGahn could land him in prison for ten years. https://t.co/5E2V15mojp pic.twitter.com/1QpKKb77mX

— PoliticusUSA (@politicususa) April 25, 2019

Trump fired McGahn’s firm. If it can be established that he did it to retaliate, that could be ten years in the slammer.