Blech, here is my admittedly very biased opinion (I am an undergraduate planning to seek admission to grad school next year).
I despise AA. Ive been busting my hump the last 3 years to make stellar grades, and the thought that someone less qualified could take my slot at that prestigious graduate school because I have the wrong skin color or my dad didnt contribute tons of money to the school sickens me.
Im a white male, with working class parents. The only socio-economic group who truly gets shafted by AA/Legacy admission policies.
That being said, Im not wholly against legacy preference, because it does help the school by pulling in tons of money.
/rant
You should be as much against legacy admissions as you are against racial preferences. Legacy admissions is basically buying a seat in a school.