James N. Mattis, secretary of Defense

Why he might stay: He’s a general. And for the most part, Trump has avoided confrontation with Mattis and stayed out his way at the Pentagon. The president has also made concessions at the request of Mattis. Last week, Trump signed a spending bill after threatening a veto. Mattis had been vocal in his support for the bill because it boosts Pentagon funding.

Mattis is a “towering figure that is indispensable to this administration and country,” said Schmidt, the Republican strategist.

“If he goes, it’s not good for the safety of our country,” he said. “He keeps Trump in line.”

Why he might go: His allies are leaving the administration. In recent weeks, it’s been announced that both Rex Tillerson and H.R. McMaster will be relieved of their duties as secretary of State and national security advisor, respectively. Mattis has also publicly split with the president on issues such as North Korea and Iran. If he becomes more vocal, that could lead to his departure as well.