"One early red flag arose in 1973, when President Richard Nixon’s Justice Department — not exactly the radicals of the day — sued Trump and his father, Fred Trump, for systematically discriminating against blacks in housing rentals.
I’ve waded through 1,021 pages of documents from that legal battle, and they are devastating. Donald Trump was then president of the family real estate firm, and the government amassed overwhelming evidence that the company had a policy of discriminating against blacks, including those serving in the military.
To prove the discrimination, blacks were repeatedly dispatched as testers to Trump apartment buildings to inquire about vacancies, and white testers were sent soon after. Repeatedly, the black person was told that nothing was available, while the white tester was shown apartments for immediate rental.
A former building superintendent working for the Trumps explained that he was told to code any application by a black person with the letter C, for colored, apparently so the office would know to reject it. A Trump rental agent said the Trumps wanted to rent only to “Jews and executives,” and discouraged renting to blacks.
Donald Trump furiously fought the civil rights suit in the courts and the media, but the Trumps eventually settled on terms that were widely regarded as a victory for the government. Three years later, the government sued the Trumps again, for continuing to discriminate.
In fairness, those suits date from long ago, and the discriminatory policies were probably put in place not by Donald Trump but by his father. Fred Trump appears to have been arrested at a Ku Klux Klan rally in 1927; Woody Guthrie, who lived in a Trump property in the 1950s, lambasted Fred Trump in recently discovered papers for stirring racial hatred.
Is Donald Trump a Racist? - The New York Times
Yet even if Donald Trump inherited his firm’s discriminatory policies, he allied himself decisively in the 1970s housing battle against the civil rights movement." http://www.nytimes.com/2016/07/24/opinion/sunday/is-donald-trump-a-racist.html