[duncan_bayne]

"but those people are banned because there is a risk of violence"

No, they're banned because their speech is so unpopular amongst a small but violent group of the population, that the Govt. would rather they weren't allowed to speak there.

That's a freedom of speech issue, not a border control issue.

If the Govt. were functioning properly, it would uphold its duty to protect unpopular speech by preventing (or at least attempting to prevent) violence directed at them. Instead, they just close their doors.