So it has come down to this: You are at liberty to exercise your First Amendment right to assemble and to protest, so long as you do so from behind chain-link fences and razor wire, or miles from the audience you seek to address.
The largely ignored "free-speech zone" at the Democratic convention in Boston last month was an affront to the spirit of the Constitution. The situation will be only slightly better when the Republicans gather this month in New York, where indiscriminate searches and the use of glorified veal cages for protesters have been limited by a federal judge. So far, the only protesters with access to the area next to Madison Square Garden are some anti-abortion Christians. High-fiving delegates evidently fosters little risk of violence.
It's easy to forget that as passionate and violent as opposition to the Iraq war may be, it pales in comparison with the often bloody dissent of the Vietnam era, when much of the city of Washington was nevertheless a free-speech zone.
It's tempting to say the difference this time lies in the perils of the post-9/11 world, but that argument assumes some meaningful link between domestic political protest and terrorism. There is no such link, except in the eyes of the Bush administration, which conflates the two both as a matter of law and of policy.
It started with Attorney General John Ashcroft's declaration, shortly after 9/11: "To those who scare peace-loving people with phantoms of lost liberty, my message is this: Your tactics only aid terrorists." This was an early attempt to couple disagreeing on civil liberties with abetting terrorists. And while I'm not reflexively opposed to the entire Patriot Act, two provisions do serve more to quell protest than terrorism.
One section invented a broad new crime called "domestic terrorism" - punishing activities that "involve acts dangerous to human life" if a person's intent is to "influence the policy of a government by intimidation or coercion." If that sounds as if it's directed more toward effigy-burning, or Greenpeace activity, than international terror, it's because it is. International terror was already illegal.
A second provision, already deemed unconstitutional in one federal court, was used to prosecute Sami Omar al-Hussayen, a Muslim graduate student at the University of Idaho who was charged with using the Internet to offer "expert advice or assistance" to terrorists by posting fatwahs and hyperlinks to a Hamas Web site. He was acquitted by a jury this summer, partly because the judge warned jurors that speech - even speech advocating the use of force or the breaking of laws - is constitutionally protected, unless directed toward inciting imminent lawless action.
An even more pernicious use of the federal law enforcement power to quash protest has been observed at presidential speeches, where the Bush team has used the Secret Service at public events to create "free-speech zones" that keep dissenters away from the president.
In 2002 Brett Bursey, a South Carolinian, was arrested for holding a "No War for Oil" sign near a hangar where Bush was speaking. The West Virginia police reported that the Secret Service had directed them to arrest a couple sporting anti-Bush T-shirts at a public speech this year. And an account by Justin Rood in Salon last week revealed that at a recent rally in Duluth, Minn., Secret Service checkpoints were festooned with photos of men posing some ostensible physical danger to the president: one was a professor active in the Green Party, another a pacifist homeless activist. Both had plans to protest the war during Mr. Bush's visit.
Michael Moore's cookie-wielding Fresno peace activists look almost dangerous in comparison. Without evidence that pacifist protesters plan to violate their own credos and bludgeon the president with their Birkenstocks, the use of the Secret Service to silence them is an abuse of executive power.
Enormous national events will inevitably be terror targets. So will the president. But before we single out the anarchists and the environmentalists and the puppet-guys for diminished constitutional protections - before we herd them into what are speech-free zones - we might question whether they represent the real danger. If we don't recognize the distinction between passionate political speech and terrorism now, it may be too late to protest later.
Dahlia Lithwick, a senior editor at Slate, will be a guest columnist during August. Thomas L. Friedman is on leave until October, writing a book. Maureen Dowd is on vacation.