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.