(always remember I am not a native speaker)
Well, you said that you would not be shocked to later find out that a Trump supporter has Nazi sympathies, right? So that means either you suspected it, or that you find that a significant amount of Trump supporters have Nazi inclinations, so statistically you're not surprised. Therefore you are associating one thing with the other, and thus one group (Nazi inclined people) with the other (Trump supporters).
If you are saying it is the opposite, I believe you -- but something is really escaping me then.
And don't get me wrong, "Trump supporter" is also quite offensive in my book...
(yes, we are derailing the thread, but I guess the guy deserved some defense)