Melania Trump vanishes from view for weeks at a time, holing up in Trump Tower in Manhattan or in Florida, where she can lie low at Mar-a-Lago. Administration officials say she is at the White House more often than the public knows, but when exactly, and for how long, these officials will not (or perhaps cannot) say for certain.

Sources familiar with the situation said that National Security Advisor and former Florida congressman Mike Waltz will be stepping down. Here's why.