U.S. Sen. John McCain tried to make his case for U.S. intervention in Syria to a mostly unsympathetic and sometimes rowdy crowd in Tucson on Thursday.

He was drowned out by cheers and jeers several times, and police removed two men who disrupted the meeting. A veteran walked out of the meeting during McCain’s answer to his question because he didn’t like what he was hearing.

McCain said he understands and accepts the public’s skepticism and cynicism about U.S. intervention in the civil war in Syria because “what happened in Iraq cannot and should not happen again.”

He said his opinions were shaped by visits to refugee camps where he met a group of women who had been gang-raped, men who had been tortured, and people who witnessed their families’ executions.

He advocated a three-part measure: degrade Syrian President Bashar Assad’s ability to use chemical weapons, give weapons to the Free Syrian Army to help the people fight Assad themselves, and reverse the momentum on the battlefield in favor of the Free Syrian Army to force Assad to negotiate his departure.

He believes the U.S. can get weapons into the right hands, and “I want to promise you there should be no American boots on the ground,” he told a crowd of about 150 people attending the town hall at the Tucson Interagency Fire Center, 2646 E. Commerce Center Place, on Tucson’s south side.

A debate about the Senate resolution is likely coming Monday with a vote later in the week, followed by discussion in the House, he said.

While most of the crowd argued against intervention, a few audience members who identified themselves as Syrian-Americans argued for it.

“We are asking you to help us. We need you. There are people dying every minute,” said Rania Hemzawi, who wore an “I Love Syria” T-shirt and a Syrian flag scarf.

Here are some of McCain’s comments about Syria from the Tucson town hall:

On the growing conflict

“This is no longer a conflict within Syria. This conflict has spread. ... The whole situation in Iraq is deteriorating. It’s becoming a base for al-Qaida moving back and forth between Syria and Iraq. Lebanon is destabilized. The king of Jordan has said he cannot stay in power with this many refugees in my  country. … This is a situation that in my view can deteriorate and engulf the entire Middle East unless something changes.”

On why the U.S. should intervene

“I am not calling for American engagement or a single boot on the ground. I am saying that throughout our history we have helped people who are struggling for freedom, and this is another case of that.”

On the victims

“World War II began because we ignored people like Hitler and Mussolini and the Japanese and others who were committing unspeakable atrocities while we turned our heads. And then we ended up with 6 million Jews being incinerated with the same kind of gas that is now being sprayed onto innocent Syrian people. And anybody who saw those pictures of those children stacked up — those dead bodies — you have got to be moved by this. You may be against American involvement, but it can’t help but break your heart when you see bodies of innocent people stacked up who have been murdered by a guy who’s a mass murderer.”

On evidence of chemical weapons use

“I promise you it is ample evidence and you will see a lot more, including intercepts, which will be made public, about how (Syrian President) Bashar Assad’s people ordered these chemical weapons to be used.”

Contact reporter Becky Pallack at bpallack@azstarnet.com or 573-4251. On Twitter @BeckyPallack