Why Not Put Protestors on the Moon?
That's how extreme "security measures" are getting as it relates to anyone trying to protest anything. Mr. Bush's people, for example, routinely remove anyone who so much as says anything unflattering or wears an "anti-Bush" t-shirt, even if the t-shirt contains no profanity.
I'm not actually certain Mr. Bush has ever seen a protestor. Since his information only comes through Condi and Karl and Card, he may really believe everyone loves him.
But it's not just Bush. He's just the most extreme example. We use "security measures" as a way of making certain that no one with a dissenting opinion gets anywhere near a corporation, a politician, or a military base. The only exception to this, of course, are so-called abortion clinics (most do far more than perform abortions - they provide vital GYN health care) where protestors can bedevil anyone and everyone.
Hell, I could get closer to protesting the GOP convention sitting in my office 50 miles south of the Canadian border than I could if I went to New York. Same is true for the Dems in Boston.
Personally, I think "security measures" are being used as a really trendy excuse for keeping the people away from the process.