"This is not a unique situation as far as Arizona is concerned," McCain said Friday. "I emphasize everyone is innocent until proven guilty, but this appears to be a problem of nationwide implications."
In recent weeks, critics of the VA system have alleged that administrators in Phoenix kept an off-the-books list to conceal long wait times as 40 veterans died waiting to get an appointment. Similar problems have since been reported in other states.
McCain hinted at possible prosecution in the Phoenix cases.
"If these allegations are true, there a violation of law. It's not a matter of resignations, it's a matter whether somebody goes to jail or not," said McCain, evoking thunderous applause from the crowd of more than 100 people.
Veterans Affairs Secretary Eric Shinseki said this week he has ordered an audit of access to care at all VA medical centers. Three executives of the veterans hospital in Phoenix have been placed on administrative leave amid an investigation into allegations of corruption and unnecessary deaths at the facility.
The McCain event came as the Veterans of Foreign Wars announced that it has established a hotline to field calls about care at VA facilities around the country. The organization has taken a less forceful tone than the American Legion, which this week demanded a major shake-up of VA ranks, including calling for Shinseki's ouster.
"We just want to hear it ourselves and not through a filter" of media coverage, said Joe Davis, director of public affairs for the VFW. "We want to hear it from the veterans directly."
He added: "There is nothing out there except allegations and conjecture until we have the IG report in hand."
While several officials have called for Shinseki to resign, McCain did not.
"I would like to see Secretary Shinseki in his capacity appearing before Congress and the American people saying what went on," said McCain, a veteran who served in Vietnam.
The chairman of the Senate Veterans' Affairs Committee has similar questions, and he announced a hearing next week on care across the VA. Shinseki will appear before the committee.
McCain invited four women onto the stage inside the Phoenix Public Library to share how a husband or father died while seeking care at the Phoenix VA. He then took questions from the crowd. Several veterans stood up to wait for a turn at the microphone. Most appeared skeptical that any solutions would be implemented.
"I have been in the VA system as well as outside of it. I have many friends that are still suffering. Are you really going to do something?" asked Marc Justin Owens, who served in the U.S. Marine Corp.
Chuck Burns, a veteran living in Gilbert, said it's taking too long for vets to get help and even for widows to get benefits.
"The VA health care system is broken," Burns said.
McCain said veterans should be allowed to pick other health care providers outside the VA. However, he said that the VA serves a crucial role in treating things such as post-traumatic stress disorder and war wounds.
"I'm advocating that we give our veterans a choice," McCain said. "I think it would be terrible if we did away with the VA."