San Francisco’s former Mayor has some advice for young progressives: President Donald Trump is popular, so come up with a better agenda instead of just sneering at him.

“Democrats need to look like the adults, not like another pack of screaming kids on the playground,” former Mayor Willie Brown wrote in the San Francisco Examiner:

It’s time for the Democrats to stop bashing President Trump. It’s not going to be easy, given his policies and personality. It might even mean checking into a 12-step program. But setting a winning agenda is like maneuvering an aircraft carrier. It takes time to change course. And if they want to be on target for the November midterm elections, the Democrats need to start changing course now. Like it or not, a significant number of Americans are actually happy these days. They are making money. They feel safe, and they agree with with the president’s protectionist trade policies, his call for more American jobs, even his immigration stance.

Brown’s article is headlined “Trump is more popular than Dems want to admit.”

Brown was born in a segregated Texas town in 1934, moved to California at age 17, worked his way through college, became a lawyer, and was elected to the state assembly in 1964. He served as Assembly speaker from 1981 to 1994 and was eventually pushed out a term-limit laws. In 1996, he was elected Mayor of San Francisco and served until January 2004.