Politics Magazine
The chart above is from a Reuters / Ipsos Poll done between March 21st and April 12th of a random national sample of 7,800 adults, with a 3 point margin of error (including 1,840 Clinton supporters, 1,370 Trump supporters, 970 Cruz supporters, and 650 Kasich supporters). Note that Clinton and Kasich supporters scored below the poll average on these racist questions, while Cruz supporters scored slightly higher than the average -- but Trump supporters dwarfed all the other candidates in supporting racist views and attitudes. Obviously, Trump appeals more to racists and xenophobes than the other candidates. That's because he himself is a racist and a xenophobe.
(NOTE -- You can click on the chart to see a larger and more readable version.)