Democrat Tony Evers claimed a big Republican scalp in Wisconsin Tuesday, ousting incumbent governor Scott Walker — although the Republican has refused to concede.

After a neck-and-neck race in which the lead changed several times, Evers declared victory early Wednesday after an influx of absentee ballots gave him a decisive surge. The result was an upset in the closest governor’s race in the state in more than 50 years.

“Given all the results we have seen tonight, I feel confident in saying to you right now: My name is Tony Evers and I’m going to be the next governor of the state of Wisconsin,” the 67-year-old school superintendent told supporters from a stage in Madison.

But his opponent’s campaign refused to concede, claiming that damaged ballots could have skewed the count. Walker’s lieutenant, Rebecca Kleefisch, told supporters to prepare for a “long, drawn-out recount.”

With nearly all the unofficial count complete, Evers led his opponent by about 1.16 percentage points. Wisconsin state law only permits a recount in votes where winning margin is 1 percent or less.

Walker, a failed Republican presidential candidate who had governed the state since 2010, tried to overcome public fatigue with his administration in his bid to retain the office. However, running for a third term is a rarity, and it was the fourth time the 51-year-old was calling on Wisconsin’s voters to turn out for him — he had also survived a recall ballot in 2012.

Throughout his campaign, Evers painted Walker as a careerist who had failed to deliver during his time in office, and presided over a slip in standards in the state’s education system.

Once a rising star of the Republican Party, Walker’s presidential bid for the 2016 race fell short, ending early in 2015. He gained prominence among conservatives, and was equally reviled by many on the left, for his attacks on organized labor. The bid to recall him in 2012 kicked off after he pushed through a law effectively scrapping collective bargaining for teachers and many public service employees.

Richard Trumka, president of the U.S.’s largest federation of labor unions, the AFL-CIO, didn’t mince words in farewelling the Republican from the political stage. “Scott Walker was a national disgrace,” he said in a statement Wednesday.