It has to be remembered that Levitical (and related) laws had to do with ritual purity or cleanliness more than anything. There is nothing inherently sinful or immoral about wearing clothing made from two different fibers. But refraining from doing that was a symbolic way for the Jews of that era to signify that they were being observant. Just as ritual circumcision of Jewish males showed primarily that they had some skin in the game. (Yeah, pun intended.)
I read the New Testament as saying, overall, that we've moved beyond these ritual observances. The letters of Paul, for example, go to great lengths to explain why Gentiles did not have to be circumcised in order to participate in the new church. In Mark 7:18-19, Jesus says, " Don't you see that nothing that enters a person from outside can defile them? For it doesn't go into their heart but into their stomach, and then out of the body." Jesus, in other words, declared all foods clean, thus overruling the Old Testament restrictions on pork, shellfish, etc. Paul, in Romans 13:9, writes, "For the commandments, 'You shall not commit adultery, You shall not murder, You shall not steal, You shall not covet,' and any other commandment, are summed up in this word: 'You shall love your neighbor as yourself.'” In Matthew 22:36-40, after being asked by a disciple, "what is the greatest commandment in the Law?" Jesus replies: “'‘Love the Lord your God with all your heart and with all your soul and with all your mind.’This is the first and greatest commandment. And the second is like it: ‘Love your neighbor as yourself.’All the Law and the Prophets hang on these two commandments.” I could cite many more examples, but I think it is undebatable that Jesus wants the world to move beyond the harsh and legalistic approach of Old Testament laws. Indeed, he points out that the Pharisees -- the most learned in Old Testament law -- had taken that law to perverse results that were in no way consistent with what God really wanted.
So while this proposed ballot initiative really doesn't have a prayer (another bad pun) of qualifying for the California ballot anyway, my main point is that I can't imagine that any educated and thoughtful Christian with an adequate knowledge of the Bible could possibly see the provisions of this initiative as comporting with genuine Christian values or principles.
R