Vermont Sen. Patrick Leahy, a Democrat who is the chamber’s longest-serving sitting member from either party, announced Monday that he would not seek a ninth term in 2022. While Leahy is famously the only Democrat ever elected to represent the Green Mountain State in the Senate—Bernie Sanders campaigned as an independent in all three of his successful campaigns—there’s little question that Team Blue’s eventual nominee will prevail in this 66-31 Biden state.

Leahy’s long career in office began in 1966 when Gov. Phillip Hoff, the state’s first Democratic chief executive since before the Civil War, appointed the 26-year-old Leahy to serve as Chittenden County state’s attorney. Leahy developed statewide recognition during his eight years as the top prosecutor of Vermont’s most populous county, and he began preparing for a 1974 Senate run even before longtime Republican incumbent George Aiken announced his retirement.

However, he still looked like a decided long shot once the seat opened up. The Washington Post didn’t even initially mention the state’s attorney, who himself had long aspired to run governor, in its list of potential candidates. Leahy had no trouble winning the Democratic primary, but he faced a challenging race that fall against Republican Rep. Richard Mallary. The state was anything but a blue stronghold at the time: Vermont had only ever backed one Democratic presidential nominee, Lyndon Johnson in 1964, and Richard Nixon had easily carried it 63-36 two years before as Mallary was prevailing 65-35 statewide.

However, the Watergate scandal had utterly devastated the GOP nationwide, and Leahy successfully pitched himself as an outsider.  Leahy, who Vermont Business Magazine’s Chris Graff writes “fashioned his image as Chittenden County state’s attorney into a high-profile, television-savvy lawman,” also emphasized public finance reform at a time when the issue was quite popular. Leahy ultimately won 49-46, with Sanders, his future colleague,  taking 4% running under the banner of the Liberty Union Party.

Leahy, who at 34 was Vermont’s youngest-ever senator when he was sworn in, had another tough battle in 1980 to stay in office. Republicans were back on the ascent, and Team Red found a formidable candidate in Stewart Ledbetter, a former official in Gov. Richard Snelling’s administration. Leahy managed to hang on by a 50-49 margin―a gap of just under 2,800 votes―even as Ronald Reagan was beating Jimmy Carter 44-38 in the state.

Few could have guessed it at the time, but 1980 would be Leahy’s last close election. Six years later, Leahy defeated Snelling, whom Reagan had recruited to run here, in a 63-35  landslide in a race that had initially looked very close. In 1992, Leahy turned back Secretary of State Jim Douglas, who would later become governor himself, 54-43; that race coincided with Bill Clinton’s 46-30 win, which started an unbroken streak of Democratic presidential victories in this one-time GOP bastion.

Leahy had no trouble in 1998 after dairy farmer Fred Tuttle, who had starred in a 1996 film about a Senate campaign, won the GOP primary before dropping out and endorsing the incumbent. Leahy’s final three campaigns were afterthoughts. He was a major force in D.C. as the top Democrat on the Judiciary Committee (though plenty of Democrats remain furious at him for allowing Republican senators to essentially veto lower-court nominees from their states), and he took over as chair of the Appropriations Committee in February.

Leahy never attracted the national name recognition of Sanders. However, his fellow Batman fans may remember his many appearances in various movies and shows, including his appearance as the voice of Territorial Governor in an episode of “Batman: The Animated Series” and as a civilian who stands up to the Joker in “The Dark Knight.” Leahy would say of his scene with the late Heath Ledger, “He scared the heck out of me with the knife. I didn’t have to act.”