The old age of senators is an age-old concern. Arizona's Carl Hayden served until age 91

Fresh concerns over the age and health of veteran Sens. Dianne Feinstein and Mitch McConnell have reignited the national conversation over how old is too old to serve on Capitol Hill.

Feinstein, D-Calif., will turn 90 on June 22 and is the Senate's oldest sitting member. She is not seeking reelection next year but has missed a lot of time in the Senate while recovering from shingles. After calls for her resignation, Feinstein has requested to be temporarily replaced on the influential Senate Judiciary Committee.

McConnell, R-Ky., returned to the Senate Monday after falling March 8 and suffering a concussion. The Senate GOP leader is 81.

The question about politician's ages — and the demand that older members of Congress retire to make way for younger blood — has come up frequently in U.S. political history, with Arizona's Sens. Carl Hayden, Barry Goldwater and John McCain all facing scrutiny about their health in their later years in office.

More: McConnell rejects Democratic plan to temporarily substitute Feinstein on Judiciary Committee

The argument generally is over whether experience and seniority beats worries about infirmity and out-of-touch perspectives.

The topic is uncomfortable, usually addressed with caution on the campaign trail and, in Arizona at least, generally has been met by voter indifference or even disgust.

Sen. Carl Hayden, D-Ariz., was in Congress for 56 years, or 20,773 days, starting when he became Arizona's first U.S. representative in February 1912. He would serve in the House until ascending in 1927 to the Senate, where he would serve a then-unprecedented seven terms. He was 85 when he ran for reelection in 1962 and chose to not seek an eighth term in 1968. He retired in 1969 at age 91 and died in 1972 at age 94.

Hayden's record as the longest-serving member of Congress would hold until 2009, when Sen. Robert Byrd, D-W.Va., surpassed it. Hayden remains the fourth-oldest member of the Senate ever, behind Sen. Strom Thurmond, R-S.C., 100; Sen. Theodore Green, D-R.I., 93; and Byrd, 92.

President John F. Kennedy and Vice President Lyndon Johnson came to Phoenix Nov. 17, 1961, to attend a banquet at the Hotel Westward Ho celebrating Hayden's 50 years in Congress. Though his tenure came before the time of many Arizonans, they still know his name, which adorns a high school in west Phoenix; the Veterans' Administration Medical Center in central Phoenix; a U.S. Department of Agriculture bee research center in Tucson; and the Glen Canyon Dam visitor center in Page.

Hayden accumulated power through his years in office. He chaired the powerful Senate Appropriations Committee and was essential to the creation of the Central Arizona Project, which had been the state's top priority for 20 years before Congress passed legislation in 1968. His importance on Capitol Hill also helped him overcome any doubts about his age and health, which were issues in his later Senate campaigns.

Campaign dirty trickers claimed Hayden dead, 'frozen in a block of ice'

During his final Senate race in 1962, Hayden was sidelined at what in those days was known as Bethesda Naval Hospital near Washington, D.C., with a virus and a urinary infection. Even so, he still was able to defeat his Republican challenger, future Gov. Evan Mecham, who at age 38 was 47 years his junior.

In a 1984 column, Ben Cole, a longtime writer in The Arizona Republic's Washington bureau who covered the 1962 Senate race, recalled how The Republic's city editor was bombarded ahead of Election Day by telephone callers claiming that the hospitalized Hayden had in fact "died and the Navy had him down in the basement of Bethesda hospital, frozen in a block of ice." The rumormongers went on to detail a conspiracy theory, Cole wrote, that claimed the aim was to keep Hayden's death a secret until after the election so that Sam Goddard, the 1962 Democratic candidate for governor, could appoint another Democrat to replace him.

(Incumbent Republican Gov. Paul Fannin would defeat Goddard in 1962, but Goddard, the father of future Phoenix mayor and Arizona Attorney General Terry Goddard, would run for governor again and win two years later in 1964.)

The frail Hayden eventually had to dispel the whispers with a hospital news conference.

Hayden, as the most senior member of the Senate, served as Senate president pro tempore from 1957 until he retired. The Senate president pro tempore is third in line to the presidential succession, but after an assassin killed Kennedy in Dallas on Nov. 22, 1963, and Johnson became president, Hayden moved up a rung behind then-House Speaker John McCormack, D-Mass.

"He got closer (to becoming president) than any of us, without even seeking it," McCain, R-Ariz., told The Republic in 2013.

Hayden's long Capitol Hill career peaked in 1968 with the approval of the Central Arizona Project, the 336-mile network of canals and pumping stations that delivers Colorado River water to Phoenix and Tucson. Signing the legislation, Johnson proclaimed Sept. 30, 1968, as "Carl Hayden Day." The CAP Hayden-Rhodes Aqueduct is another landmark named for Hayden (and in this case former House Minority Leader John Rhodes, R-Ariz.).

Hayden had announced May 6 of that year that he would not run for an eighth Senate term. "Among the other things that 56 years in the House and Senate have taught me is that contemporary events need contemporary men," Hayden was quoted as saying in The Republic.

"I tried talking the senator into running again," Roy Elson, Hayden's longtime aide, told The Republic in 2009. "He said, 'Roy, you know it. This is the time to retire.' And he came back home."

Elson, who died in 2010, sought the seat vacated by his boss but got trounced by Goldwater, R-Ariz., who had served two terms but had been out of the Senate since losing the 1964 presidential race against Johnson.

Goldwater rival accused him of 'coasting on past glory' in 1980 race

Goldwater was 60 when he returned to the Senate in 1969. He effortlessly won again in 1974.

In 1976, Goldwater underwent total hip-replacement surgery, which led to years of orthopedic troubles and pain and additional medical procedures. His Senate attendance record suffered, and that along with his health and age became issues in Goldwater's fifth and final Senate race. Now 71, he faced the younger and more energetic Democrat Bill Schulz, 49, who tried to make the 1980 campaign a contrast between the past and the future and the old and the new.

"He's coasting on past glory, and he's using past glory as a rationale for running in the '80s," Schulz said of the GOP incumbent. "I really think bygone glory has gone far enough."

In his 1988 memoir, Goldwater lamented that his campaign initially underestimated Schulz, whose wealth allowed him to mount "the most professional campaign ever waged against me" while "I was still trying to regain my normal strength."

"Our television publicity was dull and defensive," Goldwater and co-author Jack Casserly wrote. "My Democratic opponent, Bill Schulz, a multimillionaire real estate developer, was running commercials which showed me old, tired, and ill."

The 1980 election was a nailbiter for Goldwater, who won by fewer than 10,000 votes. In his book, Goldwater wrote that Schulz agreed in retrospect that it was probably a tactical mistake to have gone after him in a such a personal way.

McCain's age questioned in 2008 presidential race, 2010 Senate race

Goldwater did not seek a sixth Senate term in 1986. McCain, a former prisoner of war in Vietnam and future presidential aspirant, won the retiring Goldwater's seat and successfully defended it in 1992, 1998, 2004, 2010 and 2016.

McCain, who already had weathered questions about his age as the 2008 Republican White House nominee, turned 80 during his final Senate campaign.

Whenever his age would come up, McCain would talk about his still-living mother, Roberta McCain. For a while, his mom even joined him on the 2008 campaign trail. She would live to age 108, dying in 2020.

Shortly before the 2016 Republican primary, McCain's 47-year-old GOP opponent, former state legislator Kelli Ward, raised the possibility of him dying in office if elected to a sixth, six-year term.

Ward told MSNBC that, as a physician, she understood "what happens to the body and the mind at the end of life" and that McCain was "weak" and "old."

She made similar comments to Politico: "I’m a doctor. The life expectancy of the American male is not 86. It’s less."

Ward faced immediate blowback from the national media. "John McCain’s primary opponent has launched one of the nastiest political attacks you’ll ever see," a Washington Post headline read.

Arizona GOP primary voters rejected Ward's challenge and McCain went on to easily defeat then-Rep. Ann Kirkpatrick, D-Ariz., in the 2016 general election.

Nasty or not, Ward's grim prediction came true. McCain did not finish the term. He died Aug. 25, 2018, at age 81.

Dan Nowicki is The Arizona Republic's national politics editor. Follow him on Twitter at @dannowicki.