Sen. John McCain, R-Arizona, greets the audience as he arrives to deliver a speech in Singapore, June 3, 2016. McCain, the war hero who became the GOP's standard-bearer in the 2008 election, died Saturday. He was 81. Credit: Wong Maye-E | AP

The country is missing an “important voice for national unity” after the death of Republican U.S. Sen. John McCain on Saturday at age 81 following a yearlong battle with brain cancer, U.S. Sen. Susan Collins said during a Sunday television interview.

“What the American people should know was that John McCain was a true patriot. A man who loved his country, who would do anything to advance his country. A man who believed in national unity,” Collins, a Republican, said Sunday on CNN’s “State of the Union.”

For McCain, who was first elected to the U.S. Senate in 1987, that sometimes meant publicly pushing against his party, particularly over immigration policy and banning “enhanced interrogation techniques” condemned as torture against terrorism suspects.

That tendency to go rogue came to a head last summer when McCain joined Collins and U.S. Sen. Lisa Murkowski of Alaska to stand as the only Republicans to turn their thumbs down to their party’s bid to repeal the Affordable Care Act, also known as Obamacare. That vote came only a week after McCain’s initial cancer diagnosis.

Collins recounted that McCain struggled to decide how to vote on the “skinny” repeal, which would have undone parts of Obamacare without a ready-to-go replacement. Collins said she and Murkowski crossed the Senate floor the night of the vote to talk with McCain as he contemplated which way to vote.

“And all of a sudden, he pointed to the two of us and said, ‘You two are right.’ And that’s when I knew he was going to vote no,” she told CNN’s Jake Tapper.

Once McCain became convinced of a course of action, there was “no shaking him,” Collins said, adding that “I knew he would be there on the final vote.”

The bill failed 49 to 51, with McCain casting the deciding vote.

In a statement on Saturday, Collins, who first met McCain during her time as a staffer in U.S. Sen. William Cohen’s office, praised the Arizona senator for the “courage and character” he demonstrated in the halls of Washington and previously as a member of the U.S. armed forces.

“His word was as much his bond in Washington as it was to his brothers in arms in Vietnam,” Collins said.

McCain, who came from a line of decorated Navy admirals, served in the Vietnam War as a naval pilot, flying bombing runs over North Vietnam. During his 23rd bombing run in late October 1967, McCain’s plane was shot down over Hanoi and he was subsequently captured and imprisoned, enduring more than five years of imprisonment and torture in a North Vietnamese prison camp, according to The Washington Post.

McCain, an admiral’s son, was offered early release from the prison camp in 1968, but he refused, as it would have violated the Navy’s code of conduct, which prohibited him from accepting freedom before those who had been held longer, according to The Washington Post.

U.S. Sen. Angus King, an independent who served with McCain on the Senate Armed Services Committee, which McCain chaired, praised McCain as a “hero” who left the nation with “the clearest possible example of how a life of principle and character should be lived.”

“He was a leader in every sense of the word, the very definition of a patriot, and absolutely embodied love of country. He was irrepressible, acerbic, courageous and, often, he was a force of nature. John McCain was an American hero, and he was my mentor and friend who I will miss terribly,” King said in a statement.

U.S. Rep. Bruce Poliquin, a Republican, paid tribute to the Vietnam War hero, saying in a statement that “He fought for our Nation, on the battlefield and in Congress, and America will forever be grateful for his courage and sacrifice.”

Democratic U.S. Rep. Chellie Pingree said in a statement on Twitter: “Today we lost a true American hero, Senator John McCain, was a man who spent much of his life in service to his country. My thoughts are with his family, friends and staff. This is a very sad time for America.”

Collins, who served alongside McCain in the Senate for 21 years, recalled in her Saturday statement an encounter with McCain at Bangor International Airport a few years ago. McCain was headed to a security conference in Nova Scotia as part of a congressional delegation when their flight was diverted due to bad weather to Bangor.

When Collins went to the airport to welcome McCain and the rest of the delegation, the Maine Troop Greeters were at there as well, a sight she said was meaningful to him.

“I will never forget how touched John was by this heartfelt demonstration of gratitude for our men and women in uniform and how thrilled they were to meet a hero who served our country with such courage and character,” Collins said.

“John McCain was a great patriot and a dear friend. It was an honor to serve alongside him in the Senate. Although he will be deeply missed, he leaves behind an extraordinary legacy that will inspire Americans for generations to come,” she said.

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