Vis a vis the whole Trump and David Duke/KKK thing, let's remember that David Duke himself was once an elected Republican legislator.
From the St. Louis Post-Dispatch, February 20, 1989:
Duke said Sunday that he was extending a hand in friendship to Jews and was inviting his opponents to talk with him. But he did not mince words on where he stood on civil rights and affirmative action: ''I'm for getting the government out of our personal lives,'' he said. ''I'm not for any law for segregation or integration. The right not to associate is just as precious as the right to associate.'' In Washington, Republican National Chairman Lee Atwater pledged to have Duke censured and barred from using the GOP's name. ''David Duke is not a Republican,'' Atwater said in a statement. ''He's a pretender, a charlatan and a political opportunist who is looking for any organization he can find to try to legitimize his views of racial and religious bigotry and intolerance. ''We repudiate him in his views, and we are taking immediate steps to see that he is disenfranchised from our party.''
...
But Duke scoffed at the notion that he would be banned from the GOP. ''Is (Atwater) going to censure me for my past?'' he asked at Sunday's news conference. ''How many Republicans, how many Democrats have done controversial things in the past? The actions of Mr. Atwater are really un-American.''
And what happened? Why, the Republicans accepted Duke as one of their own.
From the St. Louis Post-Dispatch, February 22, 1989:
Newly elected state Rep. David Duke, a former Ku Klux Klan grand wizard, probably will be accepted by Republicans as one of their own if he's seated in the House, GOP legislative leaders said Tuesday. A freshman independent has said he would challenge Duke's seating, but Democrats and Republicans alike said they expected the move to fail. If the Republican Legislative Caucus lets him in, Duke will be one of 18 Republicans in the 105-member House.