A US political commentator says the UK revoked his existing visa over his criticism of Israel — bad news for free speech if it stands.

• Cenk Uygur of The Young Turks was turned away at the airport and told the UK government had canceled his two-year visa.
• He was traveling to give talks at South by Southwest London and Oxford, and only learned the reason from a press report afterward.
• The stated reason is that he criticized Israel, including saying Israel has wide influence over the US Congress.
• He argues this sets an impossible standard, since most Americans and many people worldwide criticize Israel.

Outlook: Expect a public fight over the ban and broader debate about whether the UK is policing speech about Israel at its border.