Why liberals whine about proposition 8?

Specifically I want to know:

Why it is fair to single out 5% wealthy citizens for confiscatory taxation, but unfair to single 5% gay citizens for marriage discrimination?

Please do not tell me that tax hike which you wholeheartedly endorsed is only 3%. The difference between perfectly legal civil union and marriage is also 3%. We are talking here about zero tolerance to inequality, right?
"Your correlation is absurd"

Really?
70% black Californians voted 8
96% black Californians voted Obama
Is this corelation absurd too?