If you do not see the myriad of complex laws and principles of Judaism being carried out by your parents and they are not taught to you, you will go looking for spiritual or SOME kind of belief system to fill the void. If that void is filled by materialism or Communism or whatever, the Jew by virtue of being born to a Jewish mother will not be an observant Jew and will not identify with the Jewish people. Their values will be with whatever turns them on that week. If they have fallen in with liberals to replace the Jewish community they were robbed of by their non-observant parents, their values will be those of the libs. They are still Jews according to Jewish law, but they are not living a Jewish lifestyle and their views are not based on authentic Jewish values.
The "70%" of Jews who voted for Obama were certainly mostly the type of Jews I have described here, not observant Jews who know from moral values. So it's not fair at all to lump knowledgeable and practicing Jews with Jews who were robbed of their rightful education and then declare that "70% of Jews voted for Obama".
You could say pretty much the same thing for the “Christian” liberals.