Does being Anti-Zionist equal being Anti-Semitic or is it just someone who disagrees with Israeli policy?

Anti-Zionists claim that because they disagree with the Zionist movement they are often accused of hating all Jews and are called Anti-Semitic. If the Zionist movement is a political system based on the belief that all Jews should have a national homeland and the basic right of self determination how can someone who believes it is Palestinian land be Anti-Semitic? Surely an Anti-Semitc is a person who hates Jews due to their religion, not there political beliefs. Or do i have it wrong?