When changing marriage from a state-granted privelege into a right, presuming that happens this year, the US Supreme Court may not play favorites. All consenting adults will thereafter have access to "anything goes" marriage if that is based on abandoning tradition (man/woman & "two only"). Opponents to this union between father and daughter will only have the argument "it's creepy" to fall back on. But a man using another man's anus as an artificial vagina is also very creepy, so, there you go.
Game over. Remove powers from the states to regulate and this is what Lady Justice with the blindfold on and the scales will dispense as "justice in the name of equality"...if marriage becomes a right to lifestyles in addition to race.
this is the logical next step after state sanctioned gay marriage. once that precedent is set, there can be no laws preventing any form or marriage, from father/daughter to polysexuals of all combinations.
the gay agenda is directly responsible for the destruction of western civilization. "if we don't learn from history, we are doomed to repeat it" Rome, Greece, Mayans, Egyptians, etc. when a society loses its moral compass, that society is over.