U.S. Sen. John McCain's town-hall meeting Monday in Gilbert broke down into a shouting match at times as "tea-party" activists directed their anger and frustration toward the senator over issues ranging from his characterization of them as "hobbits" to the nation's sagging economy.

At one point during McCain's first town hall since last fall, a heated verbal exchange between two men prompted the senator to call for "a modicum of courtesy" and sent town officials scurrying for more security.

"If you are not courteous to your fellow citizens here, we're going to have to ask you to leave," McCain told a crowd about 75 boisterous constituents.

The meeting began with a 15-minute speech loaded with criticism of President Barack Obama, whom McCain blamed for a surging national debt and the poor economy.

He cited Standard & Poor's recent decision to downgrade the federal government's credit rating as the latest manifestation of the administration's "unsustainable" economic policy.

But the vastly conservative crowd began to turn on the senator when he opened it up for questions, and it became clear McCain had as many critics as supporters in the room.

Kelly Townsend, a Gilbert resident and member of the Greater Phoenix Tea Party, demanded that McCain apologize for a comment made last month on the Senate floor about "tea party hobbits."

The remark came during the heated debt-ceiling debate when McCain was reading from a Wall Street Journal editorial.

"What I'm here to do is ask you for your apology . . . because that was very clumsy of you," Townsend said, adding that many tea-party followers were offended by the comment.

At first, McCain became defensive. "Is there anything wrong that I said?" McCain asked. "I don't know what to apologize for."

McCain explained he was reading from a Wall Street Journal editorial, and he meant the notion of passing a balanced-budget amendment now is fantasy, like hobbits.

"I'm sorry if it was misunderstood," McCain said. "I'm not sorry for what I said. I mean, why should I when it's the fact?"

Tea-party activists called McCain "out of touch" when the senator said he didn't know about United Nations "Agenda 21."One man described the initiative as a "takeover of the United States of America by taking over our farms."

"First, our firearms, then our farms," another man added.

McCain said no Congress would allow that to happen, but that didn't satisfy several in the room who subscribed to the theory.

Gilbert has been a hotbed for the conservative tea-party movement for a few years, and groups have organized anti-tax rallies there and had a growing influence on local elections.

Not all of the criticism directed at McCain came from the far-right, however.

Bambi Sandquist, of the San Tan Valley area, took a more moderate tone and chided McCain for his "negativity" in blaming Obama and the Democrats for the nation's troubles.

"I want something to lift me up," Sandquist said. "I want to see you guys working together, and I want to see the ideology out of it. People need to see unity and consensus.

"I have always admired you," Sandquist said. "I think you're the best man in terms of standing up for our citizens, and I miss that."