After graduating, Reid returned to Nevada and quickly jumped into politics, winning a seat in the state Assembly in 1968 at the age of 28. He set his sights on statewide office just two years later with a campaign for lieutenant governor. He had no trouble winning the primary and prevailed 55-45 in the general election at the same time as his mentor O’Callaghan was winning a close race for governor.

Reid sought a further promotion in 1974, when longtime Democratic Sen. Alan Bible announced his retirement. But while Republicans were facing a brutal political environment nationwide in the wake of the Watergate scandal in Nevada, they were able to field a strong candidate in former Gov. Paul Laxalt.

Democrats had a huge voter registration advantage at the time, and Reid enjoyed the backing of the state’s powerful labor groups, but Laxalt remained popular in the four years since he’d left office. Reid also made a mistake when he called on his opponent to disclose details of his family’s financial interests, acknowledging later, “One problem: His sister was a nun. I got killed on that.”

Reid’s prospects improved after President Gerald Ford pardoned Richard Nixon, a decision that Laxalt likened to “a hundred-pound weight around my neck,” but it wasn’t quite enough. Laxalt ended up edging out Reid 47.0-46.6, a margin of just 624 votes, which made him the one Republican to flip a Democratic-held Senate seat that year.

The following year, Reid tried to bounce back by running for mayor of Las Vegas but lost the officially nonpartisan race by a 53-47 margin to fellow Democrat William Briare. This defeat would, however, prove to be the low point, rather than the end, of what would be a very long career. O’Callaghan, who was still governor, appointed his protégé chairman of the Nevada Gaming Commission in 1977. In that capacity, Reid found himself in a conflict with the Las Vegas mob—a conflict that almost turned lethal in 1981 when his wife, Landra, discovered a bomb underneath the family car as she was about to set off for a drive.

An opportunity to return to elected office arose in 1982 when Nevada gained a second House seat for the first time. Reid decisively won both the primary and general elections for the new 1st Congressional District in the southern corner of the state. And once more, the chance to seek a higher position soon presented itself when Laxalt declined to run for a third term in 1986.

Reid’s opponent this time was ​​former Democratic Rep. Jim Santini, whom Laxalt persuaded to switch parties and run to succeed him. (Santini had also been the last member of Congress to represent all of Nevada in the House, so he was in a sense Reid’s predecessor in the lower chamber as well.)

With the GOP’s slim Senate majority on the line, Nevada became a key battleground. Santini spent the race portraying Reid as too liberal, and he used every opportunity to tie him to the top Democrat in the nation, House Speaker Tip O’Neill. Reid, who campaigned as moderate, went after his opponent’s missed votes, declaring, “If you only went to work 40% of the time you’d get fired, and that’s exactly how often he showed up.”

Reid also emphasized his opposition to storing nuclear waste in Yucca Mountain, an issue that has remained a perennial issue in Nevada politics, arguing, “Jim Santini is wishy-washy on this. I’m doing something.” Laxalt and his close ally, President Ronald Reagan, both campaigned hard on Santini’s behalf in this closely-watched contest, but Reid pulled off a 50-45 victory, and Democrats recaptured the Senate by netting eight seats nationwide.

While Reid won renomination in 1992 by a relatively tight 53-39 margin against wealthy perennial candidate Charles Woods, he turned in a 51-40 victory in the general election even as Bill Clinton was just narrowly carrying the state. But the tightest battle of his career—even tighter, it would turn out, than his contest against Laxalt—came in 1998, when he went up against Republican Rep. John Ensign in yet another expensive race.

Reid ran ads early on to introduce him to the many new voters who had arrived in rapidly growing Nevada since he was last on the ballot, and he once again used the national GOP’s support for a Yucca Mountain nuclear waste depository against his foe. Ensign, notably, even had to cancel a campaign appearance with Senate Majority Leader Trent Lott because of Lott’s advocacy for the project.

But Ensign, who turned to the longtime GOP playbook by framing his opponent as a supporter of tax hikes, ran a strong race, with more than a few observers noting that he was a much better campaigner than, as longtime political analyst Jon Ralston put it at the time, the “charismatically challenged” incumbent. Reid this time won 49.9-47.8—a difference of just 428 votes—after an election that took more than a month to resolve. In a sign of his rising influence, he was selected as his party’s minority whip even before the result was final. (Just two years later, Ensign would decisively win Nevada’s other Senate but resigned in disgrace in 2011 after attempting to conceal an extramarital affair.)

Reid finally enjoyed a landslide re-election in 2004 and became the top Democrat in the Senate following Tom Daschle’s defeat in South Dakota that same year; in 2006, he ascended to the post of majority leader after his party flipped the chamber. But Reid’s powerful role made him an easy target for Republicans both nationally and at home, especially when President Barack Obama’s popularity began to slump. He went into the 2010 campaign with approval ratings so low that fellow senators unsubtly prepared for what looked like an inevitable contest to succeed him as leader.

What happened instead was a still-famous campaign defined both by what Ralson called Reid’s “Terminator-like single-mindedness, relentlessness, and discipline turned preparation” and by egregious GOP mistakes. Reid and his team had spent years registering new Democratic voters, an effort that included the state’s historic early presidential caucus in 2008, and had built up a massive turnout machine. Reid’s network also spent the 2008 cycle successfully working to unseat up-and-coming Republican politicians—including Rep. Jon Porter and state Sens. Joe Heck and Bob Beers—before they could challenge the senator in 2010.

Reid managed to deter another formidable foe, Rep. Dean Heller, from getting in by raising copious sums of money. Ralson additionally reported that Reid played a role in moving the primary from August to June in order to ensure that he’d have more time to attack his ultimate GOP foe. However, what transpired next may have exceeded even the senator’s most ardent hopes.

In the GOP primary, Reid’s allies blitzed state Sen. Sue Lowden, whom they now viewed as their strongest foe, with the hope that they could at least damage her before a general election. But Lowden helped nuke her own campaign when she suggested, in footage filmed by Reid’s campaign, that America should return to a healthcare system where people used poultry as barter.

“[I]n the olden days,” said Lowden, “our grandparents, they would bring a chicken to the doctor, they would say I’ll paint your house.” She would never live it down. Republican voters instead nominated former Assemblywoman Sharron Angle, a decision that had severe consequences.

Reid went after Angle right after she won the primary and proceeded to spend the next several months highlighting every one of her many, many gaffes (her most infamous mistake may have been telling several Latino students that “some of you look a little more Asian to me”), but he didn’t stop there.

Reid focused on turning out Latino voters even though he knew that many of them would vote for Republican gubernatorial nominee Brian Sandoval over his own son, Clark County Commissioner Rory Reid. (The younger Reid incorrectly believed his father would not run again when he launched his ultimately failed bid.) The senator also benefited from endorsements from Republicans like state Senate Minority Leader Bill Raggio, who either appreciated his ability to look after Nevada or detested Angle.

Every single survey released in the final weeks showed the incumbent losing, but Reid’s team, as Ralston would write right after his win, had far more accurate numbers from pollster Mark Mellman that helped him bring out Democrats at a time when Team Blue faced a serious turnout disadvantage nationally. The majority leader won what would turn out to be his final race 50-45, giving his party a surprising victory on an otherwise dreary night.

Ahead of the 2016 cycle, Reid initially said he’d run once more, but following a gruesome gym injury that left him almost blind in one eye, he opted not to. The machine he built, however, helped his preferred successor, former Attorney General Catherine Cortez Masto, win a tight race to succeed him and keep his seat in Democratic hands.