NEW: Popular Republican Senator Has Died

A towering figure in Arizona politics who spent decades wielding influence on Capitol Hill has died at 84, closing the book on a congressional career that stretched from the Reagan era into the first Trump administration.

For nearly three decades, he represented Arizona in Washington, rising from the House of Representatives into the upper ranks of Senate Republican leadership. Even after initially leaving elected office, he would eventually be called back to Washington under extraordinary circumstances.

That political leader was former Republican Sen. Jon Kyl.

Kyl’s family announced his death Thursday, saying he died from complications of a neurological disease. He had previously withdrawn from public life after revealing a diagnosis that manifested as dementia.

His career in Washington began in 1987, when Kyl entered the U.S. House representing Arizona’s Fourth Congressional District. He served four terms before winning election to the Senate in 1994.

Kyl would spend the next 18 years in the Senate, eventually becoming one of the chamber’s highest-ranking Republicans.

In late 2007, his Republican colleagues elevated him to minority whip, placing him alongside Senate Republican leader Mitch McConnell and giving the Arizona senator a central role in the party’s legislative operation.

Kyl left the Senate in January 2013, apparently bringing his long congressional career to an end.

Five years later, circumstances brought him back.

Following the death of Arizona Sen. John McCain in 2018, then-Gov. Doug Ducey appointed Kyl to fill the vacant Senate seat. Kyl returned to Washington for several months before resigning on December 31, 2018.

News of Kyl’s death quickly brought tributes from political figures who had worked alongside him.

Ducey, who considered Kyl both a mentor and friend, reflected on the former senator’s decades of service.

“Jon Kyl gave Arizona nearly three decades of principled, thoughtful leadership,” Ducey wrote while announcing his condolences.

Ducey also spoke of the personal relationship the two men developed, adding, “I’ll miss him deeply.”

Former Republican Sen. Jeff Flake, who succeeded Kyl in the Senate after his initial retirement, delivered another tribute.

“Arizona has lost a giant,” Flake wrote following news of Kyl’s death.

Flake remembered Kyl for his diligence, effectiveness, integrity and commitment to public service.

Arizona Senate Republicans also honored the former senator, pointing to a political record that included national defense, taxes, conservative policy priorities and one of the most consequential issues facing the American West: water.

“Arizona has lost one of its finest statesmen,” the caucus said in a statement Thursday.

Water policy became one of the defining areas of Kyl’s career.

Long before reaching the U.S. Senate, Kyl worked as an Arizona attorney and participated in negotiations surrounding the state’s landmark 1980 groundwater law.

Decades later, he played a major role in federal legislation involving tribal water rights. In 2004, Kyl helped advance legislation establishing a massive water-rights settlement involving the Gila River Indian Community, resolving disputes that had taken years of negotiations.

His work on the agreement became an example of the painstaking, behind-the-scenes legislative negotiations for which Kyl became known.

McConnell once described Kyl’s work ethic as “legendary.”

Kyl himself acknowledged the extraordinary difficulty of getting the water agreement across the finish line.

“There wasn’t anybody else who could do that water deal,” Kyl said in a 2006 interview.

The former senator’s influence extended well beyond water policy. His years in Washington placed him at the center of Republican leadership and some of the Senate’s most consequential political battles.

His unexpected return in 2018 also put him back in Washington during the confirmation of Supreme Court Justice Brett Kavanaugh, whose nomination Kyl had helped guide before being appointed to McCain’s Senate seat.

Kyl ultimately spent nearly three decades representing Arizona in Congress — first in the House, then through three Senate terms, and finally during his brief return following McCain’s death.

His family said he died at 84 from complications related to a neurological disease, bringing to a close the life of one of Arizona’s longest-serving congressional figures.