Republican Gov. Bruce Rauner of Illinois has conceded to Democrat challenger J.B. Pritzker.

The race was framed in the media as a "battle of the billionaires," as the Democrat, a venture capitalist, has an estimated net worth of $3.2 billion, according to Forbes. Rauner, who himself has an estimated several hundred million of his own dollars, called Pritzker to concede the race, according to the Associated Press.

“Voting is an act of optimism that the levers of our Democracy still work,” Pritzker said in a victory speech to supporters, the Chicago Tribune reported. "You embody that optimism. You light the beacon fire on the hill of history that signals from one generation to another that these are the things that we stand and fight for."

Both candidates poured huge amounts of their own money into the race, with Pritzker spending $161.5 million. Rauner dedicating $58 million, according to Chicago's Daily Herald.

Rauner was elected in 2016 as an outsider in the deep blue state on a campaign slogan to “Shake Up Springfield,” a reference to the state capital.

“I call on my friends in the Democratic Party. Let us work together. Let us find common ground. Let us listen to each other, respect each other,” Rauner told supporters, according to the Tribune. “Let’s study what other states have done to move themselves forward. Let’s realize that many states have made the exact changes that we need to make in Illinois.”

But after high-profile fights with Democrats in the state legislature, and continued state budget problems due to large pension promises to government workers, Rauner's approval ratings were low.

One July Morning Consult poll conducted of all governors in the country found Rauner was the third least-popular governor in the country, with just a 27 percent approval rating. And Rauner survived a Republican primary challenge by just 2.4 points.

Despite those difficulties, Rauner campaigned on his record, citing accomplishments like passing an education funding bill, a clean energy bill, and blocking tax increases.

But that wasn't enough to hold his governorship. Rauner's general election defeat was predicted by many, and he trailed in on September poll by 22 points.