Not on private property, it isn't. Get on my porch with a larouche-sign, and you'll earn a lesson in rock-salt ;).
Different law comes into play. That would then be a trespass if you asked him to leave and he didn’t. If he’s carrying something you personally object to, you can ask him to leave. Or you can ask him to leave whether he’s carrying anything or not. But private property that’s open to the public is a completely different matter and the SCOTUS has ruled on that, too. People can indeed exercise their 1A rights on private property open to the public (shopping malls being the most common example).
The SCOTUS has also ruled a bazillion times that political speech is protected, although limitations may apply when the speech has been paid for as a function of a campaign (Campaign Finance Reform vestigial regulations). “Impeach Obama” and an unpaid for boost for Larouche would be completely protected under the 1A on private property open to the public.
“Not on private property, it isn’t. Get on my porch with a larouche-sign, and you’ll earn a lesson in rock-salt ;).”
Your house is your house. A fair is a public—or at least a quasi-public—function. I well remember that the dims and pubbies set up tents for Kennedy and Nixon at the Oklahoma State Fair.
Too often we forget that “What is right is not derived from the rule, but the rule arises from our knowledge of what is right.” (Julius Paulus)
Given the centrality of the concept of free political speech to our Republic, I don’t think it’s reasonable or right to deny a person entry to a state fair on the grounds that he intends to engage in political speech.
And if you do deny him entry, and he begins to fume and shout, well, that’s not a big deal either. Or at least it shouldn’t be. A cop who can’t handle that without acting like he’s captured John Dillinger ain’t much of a cop.