In a few years or months what happens when the Star of David is forbidden in the US? Will Jews expect Christian support?
Jewish-Christian unity has been a relatively unique thing in history. The early church was under seige both by Jews who saw followers of Jesus as blasphemous apostates and Judaizers who who were content to allow them to maintain their interest in what they saw as their unique prophet so long as they did not abandon any aspect of Mosiac law.
For centuries the two religions took divergent paths as the Christian message exploded around the world and became the dominant religion on earth on the way to the gospel message being declared to all people, tongues, and nations prior to the coming end of the world. Judaism, meanwhile, saw a series of increasing levels of apostasy, the destruction of the temple, the abandonment of large segments of the Old Testament law by Jews until today Judaism remains as little more than a loose racial identity for most.
The two religions have come together somewhat over the past 100 years as Israel has been reformed and Christian preachers have spread the message of pre-tribulation rapture.
However, the Christian would be mistaken in thinking that the Jew is any more well disposed to the cross than the Muslim, the Atheist, the Hindu, or the Buddhist.
Why would you ever imagine that the Star of David would be forbidden in the US?