This is actually my argument. That is why it's so important to set a clear example of solidarity and reject and shame racism wherever it appears. That is why that's what I expect from people, and why I'm disappointed. It doesn't take many people saying "well, sure, that's racist, but let's try to get along anyway" to make the social pressure to not be racist disappear.
To this I'd say that the cat's out of the bag. This thread being universally willing to pile on Trump supporters as racists is not going to give Trump supporters the impression that their views are opposed by almost all reasonable people. All people who intend to vote for Clinton and even Clinton herself calling Trump supporters racists at every opportunity wouldn't even do that. Because
obviously it is not the case that there is a large majority of people who find Trump disgusting. I mean, one of our two major parties nominated him for President! The Speaker of the House endorsed him! The highest-rated hosts on the most popular cable news channel are pretty much all in his corner. Trump supporters aren't blind - they can see that they're not actually all alone against the world.
The Republican establishment and conservative media failed here by deciding that supporting Trump was better than conceding the election, but given that they've done that there's not much anyone else can do to create the (false) impression that there's all this solidarity against Trump. Attempts at shaming are easily, naturally, and
correctly interpreted not as a signal of
society's disdain for Trump supporters but only as people on one side of a controversial subject verbally abusing the other. And while I'm open to an argument that shaming can be effective even in this sort of situation I think it's pretty easy to come up with counterexamples.
I think it's perfectly understandable why someone might get upset at a Trump supporter and might be a bit mean to them on the internet, but I expect that this is mostly only good insofar as it's comforting to the person who's upset and amusing to the audience. I don't think it helps stop Trump and I don't think it really contributes towards building a broader movement against the type of thing Trump is.
Edit: Like, is HuffPo's thing where they attach that note about how Trump is terrible to the end of every article about him actually
doing anything besides signalling to Trump supporters that that one media outlet, specifically, is against them? When they had to move Trump out of the entertainment section they lost, and what they're doing now is easily seen to be just throwing a tantrum that Trump is not as unacceptable to the American public as they thought he was.