No one is working harder for the impeachment of Donald Trump than Donald Trump. If we have learned anything about this president, it is that he has a compulsion to be the center of attention. He can't bear being out of the limelight and will say almost anything — no matter how offensive, outrageous or dishonest it strikes millions of Americans — to keep the public fixated on him. The more he does this, the more he risks impeachment.

Just whether John F. Kelly, the retired U.S. Marine general who is Trump's new chief of staff, can restrain his boss is unclear. This certainly is a central question hovering over the White House, and it won't be easy.

For months, Trump's behavior has posed a riddle. Why is he so self-destructive? His constant tweets deepen the country's divisions, which he promised to heal. The customary explanation is that Trump is playing to his "base," but recently, this has seemed less convincing. Opinion polls suggest his support has slipped even among loyal backers. (The latest Washington Post-ABC News poll has Trump's approval rating dropping from 42 percent in April to 36 percent in early July.)