A few days may have passed, and the news media may have moved on, but US President Donald Trump's racist rant on Twitter on July 14 has ripped open a raw wound for US immigrants of colour (this writer included), that will take a long, long time to heal.

Trump's July 14 tweet lambasting four Democratic members of Congress, all US citizens and, not coincidentally, all women of colour, could well turn out to be a historic exception.

Trump asked them to go back to the countries they came from, a totally unacceptable insult to an American citizen and a choice epithet for racists with which immigrants of colour in the west are painfully familiar.

What happened after the tweet is remarkable. Republican lawmakers, caught between a rock and a hard place, twisted themselves into pretzels. Most scurried away from reporters. A valiant few fended off Trump's critics with dubious logic. "Clearly it's not a racist comment," Andy Harris, a Maryland Republican Congressman said. "He could have meant, 'Go back to the district they came from, to the neighbourhood they came from.'" Harris would be hard-pressed to find anybody to second his opinion.

Pity the poor Republicans, little though they deserve it. As they scrambled to figure out how to defend the indefensible, Trump riled up his adoring supporters at a rally in North Carolina. The situation reminds me of an age-old observation about US politics. On hearing about an awful legislator, a wag retorted: "If you think the lawmaker is bad, you should see the constituents."

"Send them back," Trump supporters chanted as Trump waited a full 13 seconds.

This simply stunned the nation. Republican power brokers begged Trump to tamp it down.

A little chastened, Trump walked back the reaction. He wasn't happy, he said, and he quickly resumed speaking. For someone with so much practice, Trump is an awful liar. I think this is due to his unique combination of mendacity and laziness. For Trump, it's simply too much work to keep his lies straight. The news media had a field day, juxtaposing his remarks with the video clip that flatly contradicted it.

Another day, another Trump. On that day, Trump did another 180 degree turn and lambasted the lawmakers again, praising the crowd who made those racist chants as patriotic. In other words, he was walking back the walking back, if you get my drift.

Having said that, Trump deserves credit for making the Republicans honest again. He has blown away their proverbial fig leaf.

In more civilised times, Republicans were quite happy to indulge in race-baiting, but had the decency, such as it was, to be coy about it.

Lee Atwater, a pugilistic Republican strategist who advised US presidents Ronald Reagan and George W Bush, memorably described Republican President Richard Nixon's "Southern Strategy" and its historical context: "You start out in 1954 by saying, 'Nigger, nigger, nigger.' By 1968 you can't say 'nigger'—that hurts you. Backfires. So, you say stuff like forced busing, states' rights and all that stuff. You're getting so abstract now [that] you're talking about cutting taxes, and all these things you're talking about are totally economic things and a byproduct of them is [that] blacks get hurt worse than whites."'

There is a searing, poignant human aspect to race-baiting politics. Trump's racist tweets were especially painful for immigrants of colour. When the New York Times requested readers to relate their own experience of similar "Go back" form of racial harassment, it unleashed a sort of immigrant "me-too" response: An eye-popping 16,000 responses flooded in. The selected excerpts make for heart-breaking reading.

What a long way the Republican Party has come from the days of its patron saint, President Ronald Reagan. I have profound respect for this man whose policies I loathed. Reagan had made the observation that even if you live in France or England for many decades, you will never become French or English. But you can become American if you want to become one.

Like many millions of immigrants of colour, I personally felt a chill down my spine after I heard about Trump's tweets. Later, I was almost moved to tears when I was reassured by someone who has far greater authority than Trump will ever have.

"If anyone can say 'go back,' it's Native Americans." New Mexico Congresswoman Deb Haaland, a native American, wrote in the New York Times. "My Pueblo ancestors, despite being targeted at every juncture—despite facing famine and drought—still inhabit this country today. But indigenous people aren't asking anyone to go back to where they came from.

"I question the standing of anyone who would call to send my sisters and colleagues—Congresswomen Ilhan Omar, Alexandria Ocasio-Cortez, Ayanna Pressley, Rashida Tlaib—or any other American "back". As a 35th-generation New Mexican and a descendant of the original inhabitants of this continent, I say that the promise of our country is for everyone to find success, pursue happiness and live lives of equality. This is the Pueblo way. It's the American way."

Ashfaque Swapan is a contributing editor for Siliconeer, a monthly periodical for South Asians in the United States.