From a PPP poll in September:
66% of Trump's supporters believe that Obama is a Muslim to just 12% that grant he's a Christian. 61% think Obama was not born in the United States to only 21% who accept that he was. And 63% want to amend the Constitution to eliminate birthright citizenship, to only 20% who want to keep things the way they are.
More here and here. And from Greg Sargent:
Among Donald Trump supporters, nearly three-fourths (73 percent) say it’s a good idea to gather up an estimated 11 million immigrants who are in the United States illegally and send them to their home country.
And of course Trump supporters love his call to ban Muslims .
Look, I don’t think Bernie Sanders is appealing to racism when he tries to get the votes of current Trump supporters. (In fact it is BECAUSE Bernie will NOT make appeals to racism that he has no chance to garner meaningful support from Trump supporters.) I do think there’s not a snowball’s chance in hell of him getting a meaningful number of them.