A free country is exactly where you get to ask it. Only in the fascist state you desire are people not allowed to have and control their own private property, and the state can force people to use their property against their own interests. Plus, you are goal-post moving. You attacked them for not providing Nader with a private room to watch the debate, and I questioned what purpose that would serve? Now you are talking about him not being allowed in the audience.
As to whether they had the right to deny him entry, the ticket was non-transferable and thus not legit. They had every right to deny him access. Where are you getting you claim that the courts ruled in his favor? Everything I can find indicates that Nader's and all similar lawsuits have failed, as they should in any free country where a wannabe-tyrant like Nader cannot use the stormtroopers of government to force his way into private property.
You don't get to ask people with tickets to events what the purpose of their presence is.
Allowing people to attend events when they have a ticket is freedom.
Selectively throwing individuals you don't like out is not.
And this was not an issue of controlling private property from intruders.
It was an issue of not allowing a person with a valid ticket entry for no valid reason.
And Nader won this in court.
You are arguing for law breaking by the two parties.
And don't even know it.