President Trump is a racist. His racism is meaningful beyond the vulgarity of a racist president: it affects his policy. US immigration policy is certainty affected by Trump's view that African countries are "shitholes". President Trump created a committee to help increase voter suppression of minority voters. People will languish in prison because of lack of concern for criminal justice reform and his knowledge that it disproportionately affects minorities.
I am not advocating that Democrats make President Trump's racism a central issue, because many Americans have high levels of racial resentment. But, they should be cognizant of it, they should call it out, and they should fight when his racism affects the policy of the country.
Before his formal political career, Donald Trump had a history of being openly racist:
1) Racially discriminated in rental units: Trump would not rent to African-Americans.
2) Called for death of (innocent) Central Park Five: first he took out full page advertisements calling for the death of these innocent, minority teenagers. Then, after it was conclusively proven they were innocent: he still called for them to be punished.
Donald Trump solidified his position with Republicans by being explicitly racist:
3) Attacked Obama's birthplace: Birtherism is all about racism towards the first non-white president of the United States. And, it was Trump's push into the Republican party. He has never repudiated spreading and promoting this hateful lie.
4) Called Mexicans rapists: when he announced his presidency he said, "They’re bringing drugs. They’re bringing crime. They’re rapists. And some, I assume, are good people." Then, he kept saying thing like this again and again, in reference to immigrants from both Mexico and other points south.
5) Claimed Mexican-American judge was biased due to Mexican heritage: not much more explanation necessary, but here are the details.
6) Attacked Muslim gold-star parents: Trump actually made attacking Muslim gold-star parents a key part of his campaign.
President Trump has kept his racism going. And that carries a new weight and vulgarity:
7) Attacked African-American Gold-star wife: who slanders the wife a solider who just died in battle? President Trump does. He went after Myeshia Johnson again and again after her husband died in (a terribly planned) mission in Niger.
8) Declared Nazis good people: after Nazi and Confederate clad men killed an innocent counter-protester President Trump told America "Some Very Fine People on Both Sides."
9) Pardons of Sheriff Joe Arpaio and Dinesh D’Souza: D'Souza is a fringe racist troll. That is his job. And, President Trump pardoned him from the crime that he had admitted to and plead guilty. But, Sheriff Joe Arpaio is much worse. He used his office to harass innocent Latinos where and whenever he wanted. At the same time, he refused to process sexual assault cases. He is monster and President Trump pardoned him.
10) Attack on black NFL players: President Trump spent the fall of 2017 viciously attacking African-American athletes for peaceful, dignified protests designed to bring attention to policy brutality and wider issues involving racially discriminatory criminal justice.