There are certainly many groups/movements/etc that foster this but what has Trump done to do so?
Sure... lets start with the ole Obama birther crap. Racist. Trump has been spearheading that movement since 2008. Oh, you need more?
Here is what David Duke had to say about Trump right before the Party Rally in Charlottesville:
"We are determined to take our country back," Duke said Saturday. "We are going to fulfill the promise of Donald Trump. That's what we believe in. That's why we voted for Donald Trump, because he said he's going to take our country back."
Gee I wonder whoever gave the KKK the idea that Trump was going to "take our country back". Trump hired Steve Bannon, which was like burning a giant cross on the White House lawn as a smoke signal for all the rest of the white supremacists. Filled the White House with more of them like Stephen Miller. Also, many fine white supremacists in Charlottesville, which would not have happened were it not for Trump being elected.
The border wall, "shit-hole countries", the pardoning of Joe Arpaio, the Muslim ban, and this is just off the top of my head. And we are still waiting for the AMI vault to be published. If you'll remember there was a tape of Trump using racial slurs on the set of the Apprentice that suddenly disappeared right before the election. Probably a whole gang of that shit to eventually be released.