For the actor, the decade since “Mad Men” ended has been a period of personal change and mixed professional success. Suddenly, he is everywhere again.

© Adali Schell for The New York Times

For the actor, the decade since “Mad Men” ended has been a period of personal change and mixed professional success. Suddenly, he is everywhere again.

© Adali Schell for The New York Times

Harold Hamm, Trump’s energy mentor, wants to take us back to the 1990s.