Ok...you've found a boundary. You need to calmly communicate this to him when he's not been drinking...because IMPO (having lived with someone who drank too much) telling him something like that at a time when he's already been drinking, will not work. It's likely to escalate your situation and leave you ended up frustrated.
To add weight to your boundary you need to communicate to him that you are not willing to participate in arguments with him where #1 he's been drinking, #2 it's not about you, and #3 where voices are raised. YOU, have to really concentrate too when the next argument happens....not to raise your voice, and repeat your boundaries to him....then just walk away.
My point here...is don't wait for an argument to let him know this is a boundary, tell him it is now.
Also...what are the consequences. Walking away from him isn't much of a consequence for him.
