"I've never been there with John McCain because I've always felt that he should've done a much better job for the vets. He has not done a good job for the vets and I've always felt that he should've done a much better job for the vets."

— Donald Trump, interview with The Washington Post, Tuesday

In refusing to endorse Sen. John McCain, R-Ariz., in his primary election, Trump again attacked the senator over his record with veterans. As is the case with the majority of Trump's claims, his campaign did not respond to our request for clarification or information to support this claim.

We explored McCain's voting record on veterans issues to see how much merit this claim has. Has McCain "not done a good job" for the veterans?

McCain, a Vietnam War veteran who spent more than five years as a prisoner of war, has been an advocate of veterans throughout his career.

In 1991, Congress enacted the "McCain Bill" to require the secretary of defense to make public information relating to those who were unaccounted for from the Vietnam War. Since then, the bill has been amended to include the Korean War and Cold War. In the 1990s, McCain also worked with then-Sen. John F. Kerry, D-Mass., to successfully restore diplomatic relations with Vietnam.

Rather than chronicle every vote throughout more than three decades in Congress, we will focus on some of his recent efforts.

McCain was a co-sponsor of the 2014 legislation to overhaul the Department of Veterans Affairs, following the scandal that unfolded after whistleblowers alleged that dozens of veterans died at VA's medical center in Phoenix while waiting for medical care. VA's Office of Inspector General later acknowledged that wait lists may have contributed to the veterans' deaths. Patient and appointment record falsification and manipulations were then found to be a systemic, years-long problem.

McCain was not a member of the Senate Veterans Affairs Committee, but was a key negotiator for the bipartisan Veterans Access, Choice and Accountability Act. He worked with then-chairman Bernie Sanders, I-Vt., to negotiate the legislation, which made sweeping changes to veterans' access to health care for the first time in two decades.

The key element that McCain pushed was the Choice Card, to give veterans more flexibility to receive medical care from private doctors if they live far away from a VA facility or have been waiting for a certain number of days for an appointment. Many veterans groups supported this option at the time.

More recently, McCain pushed to expand the Choice Card program and extend it indefinitely. Several veterans groups opposed this proposal, saying it would increase government spending and that veterans might end up facing long wait times with private providers.

As chairman of the Senate Armed Services Committee, McCain was one of the original co-sponsors of the Clay Hunt Suicide Prevention for American Veterans Act, in 2015, which the Senate approved on a 99-to-0 vote. This bill called for VA to expand and improve its mental health services, in an effort to curb suicides by veterans.

Arizona has a large veteran population, which means veterans issues are a major part of McCain's constituent work. So far this year, his office says it has completed more than 2,000 cases relating to VA and is working on more than 750 veterans cases. In 2014, when the scandal broke, the office worked 3,500 VA-related cases — about half for people living outside of Arizona, according to his staff.

Of course, there have been critics of McCain's record even before Trump came along.

When the scandal first erupted, about 150 veterans and their supporters held a rally in Phoenix hosted by the veterans group Concerned Veterans for America. At the rally, many veterans expressed their frustration with McCain and Sen. Jeff Flake, R-Ariz., who were not in attendance, yelling their names and demanding they fix VA's wait times.

Dan Caldwell, the group's vice president for legislative and political action, said McCain has been a visible leader on veterans issues. Some of the frustrations veterans direct toward McCain is a reflection of their ideological differences with McCain and their frustrations in fixing wait times at VA, he said.

"They hope that the person can wave a magic wand and fix all the problems they have with the Department of Veterans Affairs. Unfortunately, it doesn't work that way," Caldwell said. He added that because veterans are generally more conservative, some have criticized McCain on his overall political record rather than specifically on veterans issues.

The Iraq and Afghanistan Veterans of America (IAVA) gave McCain low ratings for his record on representing the interests of the younger generation of veterans, particularly for his opposition to the 2008 G.I. bill for post-9/11 veterans. In 2010, McCain received a "D" grade from the group. IAVA no longer issues ratings and has criticized Trump for attacking McCain's record.

Garry Augustine, executive director of the Disabled American Veterans Washington headquarters, said in a statement, "Senator John McCain, a DAV life member, has been involved in a wide range of issues impacting veterans during his career." Augustine cited McCain's work on 2014 VA legislation and changes to VA's benefits system to lighten the burden on claimants filing for benefits.

Whether McCain "should have done a much better job" is more of Trump's opinion, and not readily fact-checkable. But it's clear that Trump's claim that McCain "has not done a good job for the vets" contradicts McCain's voting record on many veterans issues, from making POW information public to negotiating major overhaul legislation for VA after a national scandal over wait times.

Over the years, veterans groups have criticized McCain for certain votes that affect various interests within the veteran community, or opposed some of his proposals. But even the organizations that have criticized parts of his voting record have recognized his overall contribution to veterans issues throughout his career.