A history lesson for Bill de Blasio

Maybe Bill de Blasio needs to return to school.

The mayor, in his quixotic campaign for president, was the shrillest of his progressive rivals to lambaste Democratic 2020 front-runner Joe Biden for saying he had worked with racist Southern segregationist senators to pass legislation.

“At least there was some civility,” said the former vice president. “We got things done.”

But de Blasio, who’s near the bottom of the presidential polls, couldn’t resist.

“It’s 2019 and Joe Biden is longing for the good old days of civility typified by James Eastland,” de Blasio said, referring to the late Mississippi senator and noted segregationist. “Eastland thought my multiracial family should be illegal . . .”

For good measure, the mayor posted a photo of his black wife with their mixed-race son and daughter.

Apparently, the mayor never heard of Franklin D. Roosevelt and the New Deal. Or Lyndon B. Johnson and the Great Society? Both men made deals with racist Southern lawmakers to pass landmark legislation. How does de Blasio think Roosevelt passed the Depression-era New Deal in the 1930s? How does de Blasio think Johnson passed his civil rights and anti-poverty legislation in the 1960s?

De Blasio was joined by at least four of his progressive Democratic colleagues in lambasting Biden, although none shared the mayor’s stridency. Said Sen. Elizabeth Warren, “It’s never OK to celebrate segregationists.”

What infuriates — and frightens — many moderate Democrats is the moral superiority and perceived intellectual purity of de Blasio and the party’s progressive wing. Should de Blasio or one of his like-minded Democratic rivals capture the party’s nomination, we could have four more years of Donald Trump.

Ironically or hypocritically (choose your own here), de Blasio has made deals with people whose philosophies he claims to abhor. Take his first police commissioner, Bill Bratton, whose zero-tolerance policies 25 years ago, when homicides topped 2,000 a year, are now considered as racist by progressives. Their reasoning: In sending so many black and Hispanic men to prison, the police destroyed innumerable black and Hispanic families.

Bratton’s appointment served both de Blasio and Bratton well. Bratton returned to a job he loved. And his law enforcement credibility gave de Blasio, at least initially, a certain credibility — credibility the mayor squanders tilting at windmills on the campaign trail.

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