Talk politics.

In and of itself, it's not really a solution. More like a realization that should be obvious, but isn't, or maybe a better starting point for discussion. In the minds of many modern liberals, opposition to illegal immigration can't equate to anything else but racism. Maybe they (modern libs) truly are that simple minded and honestly believe racism can be the only possible reason, maybe they aren't, but either way- branding someone else a racist is a GREAT way to shelve discussion before it even begins.