Proposition 8 has been ruled unconstitutional. The 128 page ruling refers to other cases of a similar nature – especially Romer vs. Evans - when writing about the reasoning behind the majority opinion. The ruling includes safeguards to “insulate” and prevent it from being overturned.
“The majority summed up its ruling this way: ‘By using their initiative power to target a minority group and withdraw a right that it possessed, without a legitimate reason for doing so, the people of California violated the Equal Protection Clause [of the federal Constitution]. We hold Proposition 8 to be unconstitutional on this ground.’”