President Trump has once more disgraced his office, this time by employing the old prejudicial trope used by those threatened by ethnic and societal change — those folks should go back where they came from.

African Americans in pressing for civil rights in the 1960s were told to go back to Africa if they didn’t like the status quo. Irish American immigrants expanding their political clout in the 19th century were told to go back to their potato farms.

Trump presented a similar spin in attacking several progressive freshmen Democratic congresswomen.

“So interesting to see ‘Progressive’ Democrat Congresswomen, who originally came from countries whose governments are a complete and total catastrophe, the worst, most inept anywhere in the world … now loudly and viciously telling the people of the United States, the greatest and most powerful nation on earth, how our government is to be run. Why don’t they go back and help fix the totally broken and crime infested places from which they came,” tweeted Trump.

The targets of his attack were Representatives Alexandria Ocasio-Cortez of New York, Ilhan Omar of Minnesota, Rashida Tlaib of Michigan and Ayanna S. Pressley of Massachusetts.

For the record, all but Omar were born U.S. citizens, while Omar is a naturalized citizen.

We should be shocked that a president, in the year 2019, would stoop to such a racist approach to his political opponents, but we are beyond shock when it comes to this president. Since his campaign for president began, Trump has made his approach clear. He seeks to stoke fear about an America that is going through a major demographic shift, becoming more racially and ethnically diverse, younger — this year Millennials (ages 23 to 38) passed Baby Boomers (ages 55 to 73) — less white, less religious and more tolerant of different lifestyles.

By depicting illegal immigration as a crisis — when in fact a Pew Research Center study last year concluded that at 10.7 million the number of unauthorized immigrants in the U.S. fell to its lowest level in more than a decade — and by coloring political disagreements in a racial hue, Trump seeks to whip up an us-against-them narrative that will bring enough white and older voters to his side to win a second term.

Megan Rapinoe, a star of the world champion women’s soccer team, put it succinctly in an appearance on a Sunday news talk show: “I think that he’s trying to divide so he can conquer, not unite us so we can all conquer."

As troubling as were the president’s comments, more disturbing is that but for a few critical responses, Republicans had nothing bad to say about the president’s tweets.

Instead, Sen. Lindsey Graham, R-S.C., went all Joseph McCarthy. “We all know that AOC and this crowd are a bunch of communists,” he told Fox and Friends viewers.

Wow.

The arguments by the apologists for Trump are easy to anticipate.

They will argue that we miss no opportunity to criticize the president. Our answer: It would be our failure to ignore such grossly inappropriate rhetoric, be it from the president or any elected or appointed public servant.

They will call us apologists for the agenda promulgated by the congresswomen Trump attacked. Instead, we disagree with many of their progressive policies and espouse a more pragmatic, centrist approach to addressing the health care, immigration, cost of higher education and environmental challenges confronting the nation.

However, as Connecticut Democratic Party Chair Nancy Wyman, our former lieutenant governor, well put it, ”Whether or not we all agree on policy, it is inherent in the foundations of our government and our society that we respect one another’s right to have an opinion and share it.”

What would have been more encouraging would have been a statement to that effect from the Republican party chair as well, but there was silence from Connecticut GOP Chairman J.R. Romano.

The apologists will tell the board to stick with local issues, yet such divisive rhetoric from the president reaches into the grassroots of our community, giving license to bigots to act out.

The Democrats are a party divided, the split most evident in the House. A shift too far left will damage the party’s prospects nationally. But rather than exploit that division, Trump has again given Democrats a reminder why they must unite — to defeat him.

The Day editorial board meets with political, business and community leaders to formulate editorial viewpoints. It is composed of President and Publisher Timothy Dwyer, Executive Editor Izaskun E. Larraneta, Owen Poole, copy editor, and Lisa McGinley, retired deputy managing editor. The board operates independently from The Day newsroom.