Sez you. I think the claim that Jesus was the messiah, and that Christians seek to prove this claim by (mis)using the Hebrew scriptures, prove rather conclusively that it is a material question. If Jesus isn't Jewish, then he sure as heck ain't the messiah. You can kiss the Christian grounding in Jewish scripture and prophecy goodbye.
This is an important political/historical source of religious-based Christian antisemitism. Jews, as keepers and expert interpreters of their own sacred books in the original language, rejected the Christian theological textual basis for the claimed messianic nature of Jesus. It was awkward to claim that Jewish scripture supported something that Jews could explain it didn't.