One of his major efforts was helping President Donald Trump appoint two judges to the Supreme Court. But his parting wouldn't be entirely unexpected.
President Donald Trump tweeted in August: "McGahn will be leaving his position in the fall, shortly after the confirmation (hopefully) of Judge Brett Kavanaugh. ... I have worked with Don for a long time and truly appreciate his service!"
Trump said Tuesday he'd selected a replacement for M cGahn.
McGahn was said to have stopped Trump from forcing Attorney General Jeff Sessions to re-involve himself in the Russia investigation after Sessions recused himself last year — and from firing special counsel Robert Mueller.
McGahn has also given over thirty hours of testimony to Mueller as part of that investigation.
Addition reporting by Newsy affiliate CNN.