Homophobes get offended when I compare their anti-LGBTQ bigotry to racism.

Good.

The analogy holds: both homophobia and racism are basically taking one harmless quality of a person (be it skin colour or sexual orientation) and using it to divide the population into the privileged and the discriminated group.

There’s only two differences:

One: people can hide their sexual orientation and gender identity in order to partially avoid the discrimination – people of colour generally don’t have such option.

And second: while racism is almost universally considered evil and shameful, homophobia is sometimes regarded just an “opinion”.

So, when you call out their anti-LGBTQ bigotry as being not that different from racism, they understand how insulting a racist label is, yet they cannot find any explanation to why they are any different from one.

They aren’t. And maybe this comparison will make them understand.