I try to pronounce Spanish loanwords correctly, not because I have any respect for beaners, but because I care about linguistics, and also because Spanish is a European language anyway. That being said, pronouncing loanwords "correctly" doesn't require you to twist your speech into a foreign accent (the way pandering retards and leftists do). The way a spic says "taco" and the way I say "taco" are clearly different, even though we're both pronouncing it "correctly".