This is complicated but we are not Reddit. They would be demanding to speak to your GF so they can tell her to leave you ASAP and how best to fuck you over in the process.
If this is how she is acting now, at this age. There is probably not a huge amount of room for her to consider those ideas and change over time. I would not accept someone that acts like that.
However, talking is important. The bleeding heart is probably mostly from the media she is using and from the people she is around. She probably has friends, family or some stupid social media group/websites pushing this on her 24/7 (or all of those). Women make decisions so they are accepted (it makes them feel good), not because they are good decisions (for the most part).
I don't know what to suggest but I would simply default to logic (which she may ignore, as you have suggested). Illegals hate us and want us dead. They want to take everything from us and replace us while turning our country into the shithole they came from.
You can have compassion and empathy but talking like "trying to make better lives" is suicidal. They don't want better lives. They want to kill you and take over the life you have. They don't think the way you do, they don't believe the things you do. You are NOT the same and you need to learn that.
If she can't get that through her head she is probably a lost cause that will eventually turn into a blue haired freak and attack you in your sleep with a chefs knife because you offended "her people" somehow.
My wife is not originally from the USA and we have been together for a long time. She became a citizen before we married (we were together at that time). She loves this country and hates these people that are trying to kill it. This is our country. Not just my country. OUR country.
She would probably have far more harsh words for you than what I wrote though. You will have to decide if this is something that you can work out or if it's just not worth it and move on.
Sometimes reason can win but you have to look for the cause for why she is thinking this way and try to understand it to see why it has such a influence. If it has too strong of a hold you will never be able to bring her back to reason.
I wish you the best of luck and I hope this helps.