First, there was the angry man who told John McCain to hit Barack Obama “where it hurts.” Then came the woman who called the Democratic nominee “an Arab.”

And don’t forget the man who stood up before a packed crowd and said he was “scared” of an Obama presidency — nevermind the racially tinged cat calls and rounds of boos from McCain’s other gymnasium crowds.

The town hall format was supposed be the Republican nominee’s favorite campaign forum, highlighting his shoot-from-the-hip style, his broad knowledge on a slew of issues and his irreverent wit. He loved it so much that he challenged Obama to a string of town hall debates.

But with their potential for amplifying unscripted outbursts and attention-diverting disasters, the microphones at high school gymnasiums and basketball arenas across the swing states have gone silent during the final stretch of the presidential campaign.

McCain, a man who has prided himself on discussions with the common man, has not entertained a single question from audience members since Oct. 10, when he faced a belligerent crowd in Lakeville, Minn., that at times turned against him.

The disappearance of the town hall format from McCain’s campaign is striking, political observers said, offering a vivid example of how a signature strength became a potential liability and was abandoned. (Obama, too, has done away with the town halls, last taking questions from voters on Sept. 12 in New Hampshire.)

“The town hall format proved to be a little embarrassing for the campaign, and it built a negative picture about what this campaign is all about,” said Julian Zelizer, a professor of history and public affairs at Princeton University, adding that the encounters were “too costly.”

Over the past few weeks, McCain has replaced his beloved town halls with large rallies, press statements delivered at factories and in hotel ballrooms, “town square” stump speeches given in the center of small towns, and stops at restaurants and other local landmarks.

That could change on Sunday. Down in the polls with just a few days remaining before Election Day and apparently willing to risk the uncontrolled format, McCain is scheduled to hold a town hall meeting in New Hampshire, where independent-minded voters gave him victories in both the 2000 and 2008 primaries. The most recent polling shows Obama with a sizable lead in the Granite State.

“We think New Hampshire has always been a battleground. We wouldn’t go there just for nostalgia purposes,” campaign manager Rick Davis said in a conference call with reporters. “We are pretty committed to finishing the campaign in New Hampshire.”

Town halls are typically smaller events than rallies, making them less than ideal forums to reach large numbers of independent and undecided voters, said one senior McCain aide, who explained that only the most dedicated McCain supporters got tickets.

But the angry crowds — including people who screamed “terrorist” and “liar” in reference to Obama — worried McCain and his campaign aides, who feared a backlash from undecided and less partisan voters. McCain himself on occasion sought to soothe his crowds’ emotions after media reports started focusing on their out-of-control comments.

“We want to fight, and I will fight,” McCain told supporters earlier this month in Minnesota. “But I will be respectful. I admire Sen. Obama and his accomplishments. I don’t mean to reduce your ferocity. … I just mean to say, you have to be respectful.”