> I sure as hell wouldn't attend a conference where firearms were permitted, and I'm fairly sure even the NRA have organised events where carrying firearms or other weapons is prohibited.

in most states, the decision to permit firearms on-site is made by the facility owner and must have legal posted signs

so if a hotel in Texas doesn't have legal signage disallowing carrying on-site (no signs means you can carry), you can't just impose those rules for your own function (the correct course of action would be to hold your conference at a facility that operates policies you agree with)