The 14th Amendment, passed after the Civil War, establishes that all people born or naturalized in the U.S. are citizens. It guarantees birthright citizenship and mandates that states cannot strip citizens of their rights, requiring them to provide due process and equal protection under the law.
No it's not. An amendment needs 66% of Congressional approval, and it needs all 50 states to agree. This is my understanding, so it is not happening anytime soon. I am not CB.