A public spat has broken out after a prominent lawyer accused a critic of anti-Semitism for questioning his loyalty to Israel.

• The lawyer, who has also represented O.J. Simpson and Benjamin Netanyahu, labeled the "loyal to a foreign country" remark an anti-Semitic conspiracy theory.
• The critic fired back by noting the lawyer himself had just publicly quit his lifelong political party because he felt it had turned anti-Israel — calling that the very definition of foreign loyalty.
• The exchange highlights a bigger fight in American politics over how support for Israel intersects with party loyalty and free speech.
• Accusations of anti-Semitism are increasingly being used as a political weapon in debates over U.S. foreign policy toward Israel.

Outlook: Expect this clash to keep fueling the broader debate over Israel's influence on U.S. politics and when criticism crosses into anti-Semitism.