If the majority of immigrants voted Republican, liberals would enthusiastically support the travel ban, end sanctuary cities and build the wall!
Do you really think liberal people would be that superficial in their ideology?
Liberal beliefs come from their need to take down Trump, that's what they are about.
Not all liberals only care about taking down Trump. Some just don't agree with his policies. Also, there are a lot of immigrants who vote Republican but many liberals still believe they have the right to be here.