The two men had similar wants: money, power and respect. As mayors and governors rotated in and out, Mr. Trump and Mr. Sharpton endured. They became staples in the newspapers and on television, notably because of their say-almost-anything personas.

[How Trump and Sharpton became the ultimate New York frenemies.]

Now Mr. Trump is in Washington and Mr. Sharpton is a host on MSNBC, and their feuding is in the national spotlight (and, of course, on Twitter).

What is happening with President Trump and Mr. Sharpton?

President Trump is facing criticism over his taunts directed at four minority congresswomen, telling them to “go back” to their “totally broken” countries.

The president later attacked Elijah E. Cummings, a black congressman who represents part of Baltimore , saying that Mr. Cummings’s district is a “disgusting, rat and rodent infested mess” where “no human being would want to live.”

As my colleague Peter Baker put it recently, “When it comes to race, Mr. Trump plays with fire like no other president in a century ,” yet “Mr. Trump ritually denies any racial animus or motivations.”