1. Don’t tell the president.

That was the message Kirstjen Nielsen received when, as homeland security secretary, she became increasingly worried about Russian interference in the 2020 election. But Ms. Nielsen, pictured above last summer, couldn’t discuss it at high-level White House meetings.

Mick Mulvaney, the president’s chief of staff, said in a meeting this year that President Trump still equated any public discussion of Russian influence with questions about the legitimacy of his victory, and it was best to keep the information “below his level.”