Dan Nowicki

The Arizona Republic

Arizona Sen. John McCain's absence from Capitol Hill as he battles a deadly form of brain cancer means more than just one less Republican vote for the already narrow Senate GOP majority.

Few senators have the stature of McCain, a six-term veteran, 2008 Republican presidential nominee and former prisoner of war.

As chairman of the influential Senate Armed Services Committee, which has oversight of the Pentagon, he is a prominent voice on national defense and security matters, and outspoken enough to act as a check on President Trump when necessary.

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A regular face on the Sunday morning public-affairs TV shows, McCain also has a history of working across the aisle with Democrats on select issues, such as comprehensive immigration reform.

McCain signaled prior to his cranial surgery last week to remove a blood clot — revealed Wednesday to be associated with an aggressive brain tumor known as a glioblastoma — that he might be interested in pursuing another such bipartisan coalition. This time to fix the health care system in the event a GOP-only effort to undo the Affordable Care Act fell apart, which appears to have happened earlier this week.

McCain is held in such regard by his Republican colleagues that in 2014 he was tapped as the GOP negotiator on Department of Veterans Affairs reform, even though he didn't sit on the Senate's VA committee.

"As long as he's gone, the Senate has a lot less gravitas," said John J. "Jack" Pitney Jr., a political scientist at Claremont McKenna College in Southern California. "Because of his record and his character, his words carried a lot of weight.

"He was a heavyweight in a chamber full of lightweights."

McCain, who turns 81 on Aug. 29, on Thursday made it clear that he is by no means done with the Senate. While he has told fellow senators that chemotherapy likely is in his future, he also put his "sparring partners in Congress" on notice via Twitter that "I'll be back soon, so stand-by!"

McCain was expected to miss at least a week of Senate business because of his surgery, but treatment for the glioblastoma will certainly require him to take more time off.

In the meantime, Sen. Jim Inhofe, R-Okla., has been filling in for McCain at the helm of the Armed Services Committee. He is the Republican next in seniority on the panel. No hearings are scheduled for next week.

"It's quieter" without McCain, said Sen. Lindsey Graham, R-S.C., a close friend and ally of McCain's.

"It's hugely different because John is a fighter and he jumps into every cause no matter how hard it might be," Graham told reporters. "The energy he provides. He's coming back."

Sen. Jeff Flake, R-Ariz., said McCain's absence will reverberate internationally as well as in Washington.

"One of the most important roles he has played, obviously, over the past six months is as one who reassured the world that America is still going to lead," Flake told The Arizona Republic. "He was a calming, consistent voice when we needed it."

Flake and others say the loss of McCain in the short term is most dramatic in the health care debate, where every Republican vote in the Senate counts. The GOP controls the 100-member chamber with a 52-member majority.

Senate Republican leaders apparently still plan to try to repeal the Affordable Care Act next week even though McCain isn't expected back so soon.

On votes to confirm Trump's nominees, Republicans usually have a vote or two to spare, Flake said. It also helps that Republicans control the Senate schedule and might be able to time certain votes for when McCain is present on the Hill.

"It will make a difference in the arena, when we're debating these things," Flake said. "He's always contributing."

McCain's absence also represents a big loss of institutional memory. He first won election to the House of Representatives in 1982 and moved to the Senate after winning the seat vacated by Barry Goldwater in 1986.

That loss could have an impact on other big items still pending on the GOP agenda such as tax reform.

"Not sure that they'll actually be able to get to it, but McCain is one of only 13 senators who was actually on Capitol Hill the last time Congress passed comprehensive tax reform," Pitney said. "... At least he had some idea of how difficult it is. To take the other extreme, (U.S. House Speaker) Paul Ryan was in high school."

He will also leave a void when it comes to bipartisan cooperation in the highly polarized Senate.

"They're desperately short of grown-ups," Pitney said.

Over the years, McCain often has spearheaded efforts to bridge the divide between members of the two parties, such as when he teamed up with then-senator Russ Feingold, D-Wis., on campaign finance reform.

McCain has said he learned the value of building bipartisan coalitions to pass important legislation from the late congressman Morris Udall, D-Ariz., one of his early mentors in Congress.

More recently, McCain was the GOP leader of the "Gang of Eight," a group of four Democrats and four Republicans who collaborated on a 2013 immigration bill that cleared the Senate but went nowhere in the Republican-controlled House.

"He put the institution first, and not party, and he'll be missed in that regard," said Flake, another GOP member of the Gang of Eight. "There are others, but he was certainly a leader."

In his comments at a media event, Graham said that McCain was "excited, quite frankly, about getting a second chance to finish things that have been stuck."

"So when he comes back here, I hope he'll talk about immigration," Graham said. "I hope we'll listen to him."

Scott Celley, a political consultant who was a Senate press aide to McCain from 1987 until 1994, also predicted that McCain likely will heed his independent — or "maverick" — instincts when he returns to the Senate for the rest of his term.

"To the extent we've seen John McCain doing what he thinks is right irrespective of the consequences, we're going to see more of it for the next five years," Celley said.

Nowicki is The Arizona Republic's national political reporter. Follow him on Twitter @dannowicki.

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