As the race for the West Virginia Republican Senate nomination hurtles toward Tuesday’s primary, candidate Don Blankenship, the former coal executive sentenced to a year in federal prison in connection with a 2010 mine explosion that killed 29 men, has unleashed blistering invective against Senate Majority Leader Mitch McConnell and his wife, Transportation Secretary Elaine Chao.

He has taken to calling McConnell “Cocaine Mitch,” an allusion to drugs once found on a ship owned by the shipping company owned by Chao’s father, whom Blankenship calls a “wealthy China-person.” His ad hominem barrage, provoked by McConnell’s well-funded effort to deny Blankenship the nomination, culminated in an eye-popping TV ad in which Blankenship charged that McConnell has “created millions of jobs for China-people” and that McConnell’s “China family has given him tens of millions of dollars.” The ad pledged to “ditch Cocaine Mitch for the sake of the kids.”

What has gone overlooked amid this extraordinary clash, is that 18 years ago, both McConnell and Chao effectively sprang to the defense of Blankenship, sparing his company considerable cost and consequences for a disaster that unfolded in their home state of Kentucky in the middle of the night on Oct. 11, 2000. Here is how I described the episode in my 2014 biography of McConnell:

Three hundred million gallons of coal slurry, the viscous mix of mud, coal waste, and chemicals left as a by-product from purifying coal, broke through the inadequate buffer that separated the 68-acre holding pond of the Martin County Coal Corporation’s Big Branch Refuse Impoundment from the surrounding mine. The dark sludge poured through two miles of mine tunnels — a miner had left the area just moments earlier — before oozing out of a mountainside opening into the hilly landscape of eastern Kentucky. It found its way into two tributaries of the Big Sandy River — first Coldwater Creek, and then, after the pressure forced a break in the other side of the impoundment, into Wolf Creek — filling them ever higher until it overran embankments, spreading toward the homes lining the creek bottoms of Inez, the 500-person town that Lyndon Baines Johnson visited in 1964 to promote his War on Poverty, and covering their yards with a vast moat of goop that rose to six feet deep in places. Inez resident Mickey McCoy threw golf-ball-size rocks into the blackened creeks and watched as they refused to sink in the noxious pudding. “It was a slow-moving black smothering,” he says. There was no immediate effort by the company to alert the townspeople sleeping in the spill’s path — Abraham Lincoln “Linc” Chapman didn’t know about the sludge until he encountered it while heading up Coldwater Creek before daybreak to hunt deer. “It was a lot of chaos,” he says. “If you never saw a slurry spill it’s hard to describe it. It was like a lava flow coming down from the creek bed.”

The spill, which was vastly larger in scale than the oil spill from the Exxon Valdez, left a 70-mile path of destruction running all the way to the Ohio River, killing 1.6 million fish and countless wildlife that got stuck in the muck or drank from it, sweeping away roads and bridges, and contaminating the water systems of more than 27,000 people.

Major consequences loomed for the owner of the Martin County Coal Company: mining giant Massey Energy, which was led by Blankenship. Among the agencies that kicked into gear were the Mine Safety and Health Administration, which had issued recommendations about strengthening the holding pond walls in 1994 following a smaller spill.

A team of investigators from MSHA was on its way to alleging eight separate violations against Massey that could have resulted in hundreds of thousands of dollars of fines and laid the legal basis for criminal charges of willful negligence.

But in the midst of their work, the presidency fell to George W. Bush following the Florida recount and Supreme Court ruling in Bush v. Gore. “I don’t think I have ever felt better, including my own election victories, than the night of the Supreme Court decision,” McConnell said later.

The day of Bush’s inauguration, the head of the MSHA investigative team, Tony Oppegard, got a call from superiors alerting him that the Bush administration was declining to approve the six-month extension that had been arranged for him so he could finish the investigation. The person who replaced Oppegard, Tim Thompson, arrived in Kentucky and told Oppegard’s No. 2, Jack Spadaro, to scale back the investigation. The team had 30 people left to interview, but the new manager told them they had time for only six. “We were told, ‘Boys, you need to close out your investigation,’” Spadaro told me in an interview for the book. “We said, ‘No, we’re not done.’ He said, ‘You’re done.’”

MSHA, which is part of the Labor Department, was overseen by the secretary of labor: Chao, whom Bush nominated upon taking office. Chao, who had previously led the Peace Corps and United Way, turned to her husband’s associates to fill out her office. She hired as her chief of staff Steven Law, who had served six years as McConnell’s chief of staff (and went on to co-found the super PAC Crossroads GPS with Karl Rove.) She hired as her spokesman McConnell’s former spokesman. And the new director for MSHA, a former Utah coal operator named David Lauriski, hired as one of his top aides yet another former McConnell staffer, Andrew Rajec, who began attending many of the meetings of the Martin County investigators.

In my book, I described what happened next:

Thompson pushed to have the case against Massey reduced to just two violations with a fine of $55,000 each, rather than the eight that Spadaro and his fellow investigators believed were justified. One day in April 2002, Thompson got a call from MSHA headquarters outside Washington, D.C., after which, with the investigators watching, he crossed out a section of the draft report that called MSHA to account for its lax oversight.

That was enough for Spadaro. Seeing where things were heading, he tendered his resignation in a letter published in the local papers. ‘I do not believe that the accident investigation report, as it is being developed, will offer complete and objective analysis of the accident and its causes,” he wrote. As word of Spadaro’s protest spread, Elaine Chao dismissed it by telling a reporter, “It’s time to call off the MSHA food fight over the Martin County Coal Slurry investigation.”

Soon afterward, Spadaro became the target of an internal audit. When he was called to MSHA headquarters outside Washington, D.C., to be reprimanded, MSHA officials went into his office in West Virginia to confiscate his files and hard drive. They picked apart his family photos to search for incriminating evidence he might have tucked inside the frames. A few months later, he was fired. He challenged his termination and had it reduced to administrative leave, but when the agency then demoted him and ordered him to a post in Pittsburgh, he quit.

Meanwhile, the investigation sputtered to a close. In April 2002, MSHA cited Martin County Coal with just the two violations — and its case for those was so halfhearted that one was later dismissed by an administrative law judge and the other reduced to a mere $5,600 fine.

What was particularly striking about the light approach taken by Chao’s Labor Department was that it would have been easy for the Bush administration to use the disaster as a political weapon against its predecessors — to blame the disaster on the lax oversight by Bill Clinton’s MSHA. Taking a stronger stand on the spill would’ve been a way to stand up on behalf of the people of eastern Kentucky — her husband’s constituents.

But that also would’ve meant coming down hard on an industry that had, by 2000, swung firmly behind the Republican Party and McConnell in particular. Over McConnell’s career, his fifth-biggest source of campaign contributions was Peabody Energy, the largest coal company in the world. Between 1997 and 2000, when he led the National Republican Senatorial Committee, the coal industry gave $584,000 to the group, making it one of the group’s staunchest supporters.

And Massey? It hadn’t given the NRSC anything. That is, not until 2002, when the investigation was still pending. That year, it cut a $100,000 check to the group.

As Spadaro saw it, it was pretty plain what had happened: “It was Mitch McConnell who fired Jack Spadaro,” he told me. “I’ve been around a long time and I swear this was one of the most outrageous things I’ve ever seen. It was one of the most blatant circumventions of the law and it was all orchestrated by Mitch McConnell’s people.” (McConnell’s office did not respond to requests for comment, nor did Chao’s office or Blankenship’s campaign.)

Fast forward to 2018. Massey Energy no longer exists, having been subsumed by Alpha Natural Resources. West Virginia has become a stronghold of Trump country, not least because of his outspoken support for the coal industry — he won the state by a whopping 42 percentage points. Blankenship is seeking with his campaign to tap into the same iconoclastic fervor that drove Trump. But McConnell calculates that even in West Virginia, the party’s best odds for knocking off Democratic Sen. Joe Manchin in November do not lie with someone who not long ago was behind bars in connection with the deaths of 29 West Virginians — and whose primary residence is a $2.4 million villa with palm trees and an infinity pool near Las Vegas.

And guess what one of the top targets has been for the barrage of attack ads against Blankenship by the McConnell-allied group, Mountain Families PAC? One 30-second spot in frequent circulation says Massey Energy pumped “toxic coal slurry” into local drinking water. The narrator asks, “Isn’t there enough toxic sludge in Washington?”