The Note: The McCain legacy finds no obvious heir

The TAKE with Rick Klein

There's comfort in declaring, as the nation mourns a hero and a patriot, that the legacy of Sen. John McCain lives on.

But good luck finding that legacy in today's politics, in McCain's party, and especially in his home state this week.

The truth is there is no obvious heir to the McCain legacy in public life today. The president of the United States is in many ways an anti-McCain figure – making his feuds with the late senator personal, and creating an ideology that centers on his personality.

All three of the Republicans vying for a Senate seat in Arizona in Tuesday's primaries have pledged loyalty to President Donald Trump. Just hours before McCain passed, one of those Republicans declared on the trail that the state "cannot afford" to "elect another senator who is cut from the same cloth as Jeff Flake and John McCain."

The nation can use a touch of McCain's stubborn optimism at this or any moment. It could also remember his gallows humor, and a favorite McCain quote comes to mind – one he invariably delivered with a smile: "In words of Chairman Mao, ‘It's always darkest before it's totally black.'"

The RUNDOWN with MaryAlice Parks

In the two states with primary voting Tuesday, Florida and Arizona, several national issues hit close to home, including immigration, border security, environmental protection and gun control.

Sunday's mass casualty shooting in Jacksonville, Florida, put that last topic -- the debate about gun safety -- back in the spotlight for sure.

David Hogg, one of the student leaders who survived the shooting in Parkland, Florida, last February, when 17 people died, and who helped build a new national movement of youth activists working the issue, encouraged people to confront U.S. senators in the nation's capital Tuesday.

Florida's Democratic Senator Bill Nelson, who is in a tough reelection fight, tweeted: "Word of another tragic mass shooting in our state brings shock and outrage." The state's Republican governor Rick Scott, who is running against Nelson for his Senate seat, rushed to Jacksonville in light of the horrific news of another high profile shooting in his state.

It has been more than seven years since former Arizona congresswomen Gabby Giffords was shot in the head at an event back in her district. In the last several years, Giffords and her husband have become an effective and prolific campaign team, supporting gun safety legislation and candidates ready to back reforms.

On Sunday, Giffords wrote, "The nation once again looks to Florida with grief and heavy hearts. The massacre in Jacksonville is yet another devastating indictment of this country's inability to keep our kids safe."

The TIP with Arlette Saenz

The McCains and the Bidens share a special bond.

Last year, the country watched as former Vice President Joe Biden publicly consoled Sen. John McCain's daughter Meghan as her father battled brain cancer -- the same disease that claimed the life of Biden's son Beau. "Beau talked about your dad's courage, not about illness, but about courage. So there is hope, and if anybody can make it, your dad [can]," Biden told her on ABC's The View.

That moment -- the shared understanding of a loved one fighting for their lives against a grim disease -- opened up a new kind of relationship for Biden and the younger McCain. As she recently told Glamour, "I talk to him all the time, and he checks in on me all the time." Biden was in contact with Meghan at the end of the week, an aide to the former vice president said, as her father neared his final days.

Biden was asked to speak at a memorial service for his decades-long friend McCain in Phoenix on Thursday, an aide to the former VP said -- part of a five day span of memorial events for McCain. The former senator will first lie in state at the Arizona State Capitol on Wednesday -- what would have been his 82nd birthday. He will also lie in state at the U.S. Capitol on Friday, where Senate Minority Leader Chuck Schumer said he will introduce a resolution to rename a Senate office building after McCain.

On Saturday, former presidents George W. Bush and Barack Obama will reportedly both eulogize the senator at a memorial service at the Washington National Cathedral. Bush's spokesman told ABC the president was "honored to have been asked to speak."

And on Sunday, McCain will be laid to rest at the U.S. Naval Academy in Annapolis -- where he started his life of service to his beloved country.

WHAT YOU NEED TO KNOW TODAY

QUOTE OF THE DAY

"The important thing is not to look back and figure out all of the things that I should have done - and there are lots of those - but to look back with gratitude. You will never talk to anyone who's as fortunate as John McCain." – The senator, veteran and GOP maverick John McCain in the HBO documentary "John McCain: For Whom the Bell Tolls," which debuted about three months before his death.

THE PLAYLIST

ABC News' "Start Here" Podcast. Monday morning's episode features ABC News Chief White House correspondent Jonathan Karl and ABC News' Ron Claiborne reflecting on their time covering the late Sen. Jon McCain on the campaign trail. And, ABC News' Meghan Keneally checks in from Arizona on what McCain's death means for Tuesday's Republican primary. https://bit.ly/2Ohkpz8

NEED TO READ

John McCain, a hero and leader who took causes more seriously than himself: ANALYSIS. McCain learned long ago - through a life that included deep suffering, both physical and mental - not to take himself, or things said by his critics, too seriously. (Rick Klein) https://abcn.ws/2PC2nbv

McCain will lie in state in Arizona, then at US Capitol, funeral details show. The family of Sen. John McCain has released details of his funeral and memorial services, with the ceremonies to begin in Arizona and end at the National Cathedral, where speakers will include former President George W. Bush. (Maia Davis) https://abcn.ws/2oacpE5

Inside John McCain's 'Three Amigos' friendship with Sen. Lindsey Graham and former Sen. Joe Lieberman. "It was so classically American," Lieberman, who retired from the Senate in 2013, said. "If you looked at our biographies, the three of us couldn't be more different. Really I mean, religiously, geographically, our own experience. Yet there we were in the U.S. Senate together, and we became just the fastest of friends." (Arlette Saenz) https://abcn.ws/2wgS3xp

John McCain's death means potential legal battle to fill his Senate seat. The timing of McCain's death results in a complicated process that could end up in a court battle in a state that will be key to determining the balance of power in the U.S. Senate this midterm cycle. (John Verhovek) https://abcn.ws/2PGPQDy

John McCain's complicated relationship with President Trump. Trump's fixation on the former presidential nominee seemed to begin well before he came to Washington. Back in 1999, Trump insulted McCain's military service, a foreshadowing of his message on the campaign trail. (Ali Rogin) https://abcn.ws/2MTZZhz

Trump's biggest legal danger is from US prosecutors in New York, not Mueller: Dershowitz. "I think [Trump] has constitutional defenses to the investigation being conducted by Mueller," into Russian interference in the 2016 election, said Alan Dershowitz, a Harvard Law School professor emeritus on ABC News' "This Week." (Mitchell Alva) https://abcn.ws/2P8mGfj

Sun Belt showdowns: What to watch for in Tuesday's primaries: ANALYSIS. Two big, diverse, and scorchingly hot states that were key to President Donald Trump's 2016 victory highlight the last major multi-state day of voting in the 2018 primaries. Voters in Arizona and Florida - plus Oklahoma, where there are a few scattered runoffs - will choose candidates for the midterms on Tuesday. (Rick Klein) https://abcn.ws/2Nl61oB

How the environment has become a key factor in Florida's elections. As Florida reckons with two algae phenomena -- a blue-green nutrient-rich algae in Lake Okeechobee, and the naturally occurring red tide in the Gulf Coast shores -- the midterm elections are heating up in the Sunshine State. Floridians say they have one thing on their mind: how to protect their environment and their economy. (Lissette Rodriguez) https://abcn.ws/2BNPVlT

In Florida Senate race, Rick Scott treads carefully around Trump. Since launching his U.S. Senate campaign to unseat longtime Democratic Sen. Bill Nelson in April, Florida's GOP Gov. Rick Scott, an early and vocal Trump supporter, has taken a markedly cautious approach to a president who has consistently injected political chaos into an already uncertain midterm election landscape. (John Verhovek and Lissette Rodriguez) https://abcn.ws/2MPVm8q

Pope Francis declines to comment on allegations of sexual abuse cover up in DC. In the midst of an already contentious visit to a country ripe with anger over neglected abuses within the Catholic church, Pope Francis declined to address the contents of a letter released Sunday morning alleging that he knew about sex abuse allegations against former Washington, D.C., archbishop Cardinal Theodore McCarrick for years and didn't take proper action. (Cheyenne Haslett) https://abcn.ws/2MSyYv6

The Washington Post reports that Trump nixed a statement prepared by the White House praising McCain, telling senior aids he wanted to post a brief tweet instead. https://wapo.st/2BQdQ4e

Election experts are raising concerns about reports that teenagers hacked "clones" of state election systems at Def Con, a hacking conference held last month in Las Vegas, according to ProPublica. https://bit.ly/2Lup7Xj

The Note is a daily ABC News feature that highlights the key political moments of the day ahead. Please check back tomorrow for the latest.