I have previously defined antisemitism as an egregious form of discrimination. If you accept my definition, it would not be antisemitic to support the replacement of the Jewish state with a single secular entity that theoretically and practically provided Jews and Arabs with equal rights. You would have the heavy burden of proving that such an entity could actually exist in the real world, but you would not be an antisemite.
Right-wing Israeli nationalists view the issue differently. For them, the world is already divided into Christian, Muslim, Buddhist, and Hindu states. To deny Jews the right to a state of their own is consequently a form of discrimination and, therefore, antisemitism.
Whatever you may think of the notion of Muslim states, the fact of the matter is that the United States is not legally a Christian nation, and discrimination against Jews is unlawful throughout Europe and Latin America. The right-wing Israeli line of reasoning is only valid as applied to America if you embrace the ahistorical position of MAGA Christians that they are entitled by God to rule our nation.
If you ever wondered why the right-wing Israelis are closer to American fundamentalist Christians than to American Jews, that is your answer.