For nearly a decade, Stephen M. Sweeney, the second most powerful lawmaker in New Jersey, seemed truly unassailable. He boasted deep ties to the most feared political power broker in the state and unyielding support from the influential building trade unions. Four years ago, the state’s teachers’ union spent more than $5 million to unseat him. He won by 18 points.
This year, his challenger was Edward Durr, a truck driver for Raymour & Flanigan, a furniture chain, who had never before held office. His campaign video was shot on a smartphone.
Yet Mr. Sweeney, the State Senate president and a Democrat, was ousted in a shocking political upset by Mr. Durr, a Republican, as voters opted for a political unknown in a result that immediately rattled the political moorings of the state. Voters also nearly ousted Gov. Philip D. Murphy; the governor narrowly won re-election over his Republican challenger, Jack Ciattarelli, leading by 1.6 percentage points.
But it was Mr. Sweeney’s loss that was perhaps best emblematic of the predicament facing Democrats in suburban, exurban and rural communities.
The Associated Press called the race on Thursday morning, as Mr. Durr maintained a 2,298-vote lead over Mr. Sweeney with all precincts counted.
Though Mr. Sweeney’s district in the southwestern part of the state has never been deeply blue like the northeastern counties, it has reliably elected a Democrat since its creation in 1973, save for one year when the Democratic incumbent switched parties.
Mr. Sweeney held a vise grip on the district, largely composed of blue-collar suburbs just south of Camden and poorer, rural areas, thanks to powerful allies and a decidedly moderate record, playing up his background as an ironworker and union leader.
But as support for Democrats eroded in the suburbs and evaporated in rural areas in both New Jersey and Virginia, Mr. Sweeney found himself facing a surge in Republican voters and a loss in support from the working-class backing he had so often relied on; being a Democratic lawmaker during an era of coronavirus lockdowns, mandates in schools and dysfunction in Washington was enough to erode what was once unshakable backing.
In Gloucester County, Catherine Biasiello, 70, said she is a registered Democrat who voted for Mr. Durr because she is unhappy with the state’s high tax rate, and because she disapproves of the state’s closure of public schools during the pandemic.
Ms Biasiello, 70, who lives in West Deptford, said Mr. Sweeney “could have stepped up” to oppose the school shutdowns but did not. “He could have influenced the governor,” she said.
Mr. Sweeney’s loss amounts to a seismic restructuring of political power and influence, leaving a substantial vacuum in the State Legislature; he had held the post of senate president, with the ability to set the legislative agenda, for nearly 12 years.
In the Trump era, Republicans were seen as doomed to a permanent minority in New Jersey, as voters’ deep contempt for the former president was strong enough to turn the long-held Republican suburbs blue; Democrats flipped four House seats in the 2018 midterm elections.
But the surprising defeat of Mr. Sweeney, coupled with Mr. Murphy’s slim margin of victory and unexpectedly tight races involving popular rising Democratic stars in the state like Vin Gopal, a state senator from Monmouth County, reveals a Republican Party that seems to be marching back to relevance.
Mr. Ciattarelli’s efforts and spending led the way, allowing lesser candidates like Mr. Durr, who lives in a house next to his mother in southern New Jersey, to gather momentum.
Mr. Durr told news outlets that he had spent $153 on his campaign, but financial disclosure reports indicate he spent roughly $2,200 on his race. His meager campaign included the 80-second campaign video, where he accentuated his working-class roots with an opening scene of his stepping down from his truck cab, and ending with his riding away on a motorcycle. His victory was announced on the same day Mr. Durr was on a shift driving his truck.
With barely any attention given to the race, Mr. Durr remained largely unvetted and unknown to the general public. On Thursday, old posts on social media by the candidate began circulating, including one reflecting support for “both sides” of the violent racist rally in Charlottesville, Va., in 2017 and another condemning Islam and disparaging the Prophet Muhammad.
Mr. Durr did not respond to several requests for an interview. But in an impromptu news conference outside of his house on Thursday, Mr. Durr nodded to an electorate he saw as angry.
“It didn’t happen because of me,” he said. “I’m nobody. I’m absolutely nobody. I’m just a simple guy. It was the people. It was a repudiation of the policies that have been forced down their throats.”
Mr. Durr then took his three pit bulls on a walk.
His campaign, which largely consisted of his video, lawn signs and door knocking, projected more grievance than platforms, taking issue with the coronavirus policies of Mr. Murphy and claiming Mr. Sweeney “sat by and watched.” He also focused on the state’s high cost of living.
“The Senate president has spent 20 years in Trenton: higher taxes, increasing debt, and a rising cost of living,” Mr. Durr says in his video.
Mr. Sweeney, in a statement released on Thursday, did not concede.
“The results from Tuesday’s election continue to come in, for instance there were 12,000 ballots recently found in one county,” Mr. Sweeney said. “While I am currently trailing in the race, we want to make sure every vote is counted. Our voters deserve that, and we will wait for the final results.”
Democrats, of course, still maintain single-party control over the entire state government, but Mr. Sweeney’s loss nonetheless shocked the forces that have long controlled Trenton.
Rarely did a governor’s priority reach the floor without Mr. Sweeney’s approval.
In the first two years of Mr. Murphy’s term, before the pandemic settled in, Mr. Sweeney served as an obstacle to the governor’s expansive progressive agenda, further burnishing his moderate Democratic bona fides by pushing back on increases in budget spending and a plan to tax the wealthy. While Mr. Murphy was largely able to come to an agreement with Mr. Sweeney and enact his agenda, the Senate president was often the most powerful counter force in a state controlled by Democrats.
“He was able to impose his will on legislation,” said Joe Vitale, a Democratic state senator. “He was a force of nature. So it will be a loss for those of us who respect him and support him.”
Mr. Sweeney was closely allied with George E. Norcross, an insurance executive and powerful power broker whose stranglehold on southern New Jersey politics lead many to see him as a shadow governor. The two remained close during both Mr. Murphy’s administration and former Gov. Chris Christie’s eight years. Without Mr. Sweeney at the helm of the Senate, and with other Democratic losses in the southern part of the state, Mr. Norcross may no longer possess the ironclad control to shape state policy, though he still counts numerous legislators as allies.
In an interview, Mr. Norcross described Mr. Sweeney as “the Lyndon Johnson of the State Legislature” who “brought order to the chaos.” He said the sudden swelling of Republican turnout and independents’ anger “happened with such warp speed, that there was nothing that could have been anticipated or done, because it’s not like we didn’t have the money available to do it.”
He added that the Democratic Party will need to change, both in the state and around the country, to win back voters.
“The Democratic Party is going to have to, and candidates for office are going to have to, redefine themselves as fiscally responsible legislators and ones that are going to spend government money wisely and not recklessly as is portrayed,” Mr. Norcross said. “They can’t be defined as wanting to defund police or socialist.”
Mr. Sweeney’s loss sets up a wide open race for his successor. Nicholas Scutari, a Democratic state senator from northern New Jersey, is seen as a possible candidate to replace Mr. Sweeney in the senate leadership. Troy Singleton, a Democratic state senator from southern New Jersey, also has been mentioned as a possible replacement, among many other candidates.
Ed Dobzanski, 56, a union truck driver from Gibbstown, N.J., said he voted for Mr. Sweeney because of the Senate president’s long support for trade unions, but he thought his rival’s victory reflects a public desire for change.
“I think this is a backlash of the same people being in the same positions a long time,” he said. “People just wanted change, they are tired of career politicians.”
Jon Hurdle contributed reporting from West Deptford Township, N.J.