I don’t have to guess what he would say. I can look at what he did say.
I grew up on superhero comic books, among other things. And, to be honest, a lot of my personal and ethical philosophy was influenced by them. And Captain America was one of the biggest of those influences. (And Superman. Everybody snickers when he says he’s here to fight for Truth, Justice, and the American Way. Only he’s not joking. Or he wasn’t back in the day anyway.)
I read this comic way back when, It was one of my favorites at the time and the lesson it gave stayed with me over the years. Freedom must be freedom for everyone–whether we agree with them or disagree with them. Even when we are violently opposed to them. Perhaps especially when we are violently opposed to them.
So what did Cap have to say on that subject?
I am pretty much a free speech absolutist. Does not matter how odious one finds someones speech. Censorship is not appropriate. Violence is not appropriate. The correct response to odious speech is more speech. Speak in opposition. Point out why they are wrong. You can point out why they are wrong, can’t you? Clearly, unemotionally, and objectively? (If you can’t, you might want to ask yourself why that is.)
But recognize that the people saying words you despise have the same right to speak them that you do yours.