Then, on Sunday, when Rudy Giuliani, who has dodged nearly every interview request (even one from the conservative bible, the National Review), finally relented and appeared on “Meet the Press,” he answered questions about his mistress and his poor judgment as if he had just inhaled laughing gas. Of course, it was obvious once he bared those fangs that Giuliani would have bitten Tim Russert on the neck and sucked every drop of blood from his body if he had the chance.

If a Bronx cheer is really a boo, maybe a Bronx laugh is really a glare.

This wasn’t always the case with Empire State empire builders. Theodore Roosevelt played the blustery fool sometimes, but no one ever called him a phony. His fifth cousin Franklin wasn’t always on the level; his laugh, like so much else, was a weapon of manipulation. But it sure made you feel better, “as joyous, hearty, rolling, thunderous laughter as ever was heard on this sorrowful globe,” was the way the writer Fulton Oursler put it.

Nelson Rockefeller’s gruff humor seemed genuine enough (though his wife Happy’s happiness could be a bit forced). Mario Cuomo would sometimes smile to get himself over a rough patch, but his mirth gauge seemed in working order. I can still hear Pat Moynihan’s fabulous “Ha!” For all his blarney, humor resided in a zone of sincerity he could not bring himself to breach for political convenience.

Some non-New York presidents have been no slouches in the phony humor department. Jimmy Carter’s famous toothy grin masked an essentially humorless man. Ronald Reagan’s devastating “There you go again” jab at Carter in a 1980 debate was delivered with a rueful smile that was all craft. And George W. Bush’s nervous “heh, heh, heh” is a sure sign he’d rather be somewhere else.

But Hillary and Rudy are in a fake-laugh league of their own.

Let’s give her the benefit of the doubt and assume Clinton thought the “socialized medicine” question was funny because it was so predictable. But how about her tittering answers to Bob Schieffer, Harry Smith, Diane Sawyer and others? When she got YouTubed on it, her aides canned the laugh overnight.

By Chris Matthews’s count, Giuliani laughed 15 times during his “Meet the Press” appearance, one of the great TV grillings of all time (e.g., Russert: “Would it be appropriate for a president to provide Secret Service protection to his mistress?”). Because certifiable phoniness is apparently preferable to looking wounded or overly defensive, we can expect to see Rudy circling the laugh track anytime anyone goes after him. It reminds me of the caption Esquire routinely used under a picture of a smiling Richard Nixon (the “new Nixon”) when he ran in 1968: “Why is this man laughing?”

So we’d better get used to that google-eyed chuckle when reporters bring up his hostile attitude toward dissent in New York, his placing of the emergency command center in the World Trade Center after it had already been bombed in 1993, his use of on-duty police officers to take his mistress shopping and walk her dog, his attempted unconstitutional power grab when his term ended, his recommendation that Bernie Kerik, who was associated with people who themselves had suspected mob links, protect the nation from terrorism, his still-undisclosed profiteering off of 9/11 and whatever else might be relevant to predicting the temperament he would bring to the laugh riot that would be his presidency.

One of the questions that the 2008 handlers in both parties will likely discuss when they all get together is whether laughing works. Should it go into the damage-control toolbox with spin and counterattack?

Right now, the answer looks like no. Clinton actually has a nice sense of humor in private, but her fake laugh just reinforces the rap that she’s inauthentic. Giuliani can also be funny with friends (especially if you like your humor with a nasty streak), but he’s not a good enough actor to yuk his way through the muck.

So the verdict is in. Smile? Of course. Laugh? It’s a gaffe.