It's the Philadelphia fan base.
The following is my personal (probably somewhat biased/tainted) opinion, but:
The archetypical baseball player who will be loved by Phillies fans is: 1) white (anglo); 2) smallish; 3) "gritty" - gets dirty, plays visibly "hard" or aggressively; 4) emotional - his frustrations are evident, he doesn't "hold it in; 4) of middling actual talent, but works to overcome that.
Now, the phans have adopted lots of guys who don't have all of these characteristics - typically because their strengths in some areas offset the things the don't have. But if you're not white, or you don't appear to be "grinding" (regardless of actual performance), or you never seem to get upset, you have a strike against you. If you're obviously talented, but you're not contending for MVP, you have a strike against you. If you have multiple strikes, you're in deep trouble.
If you're latino, and the game comes easily, so it doesn't appear you're trying hard, and you don't run into walls, you're in trouble... even if you're one of the best players ever to grace the uniform. If you're white, but introverted or studious, and don't show emotion, you'd better be REALLY good, or they're not going to warm up to you... and even if you're HOF caliber, it could take a decade for the phans to see what's in front of their faces.