(Reuters) - Republican Brian Kemp’s campaign said on Wednesday he had won Georgia’s high-profile governor’s race, but Democratic candidate Stacey Abrams vowed not to concede until all ballots were counted.

“Simply put, it is mathematically impossible for Stacey Abrams to win or force a run-off election,” Kemp spokesman Cody Hall said in a statement Wednesday evening. “Brian Kemp will now begin his transition as governor-elect of Georgia.”

Abrams, 44, is trying to become the first black woman elected governor of a U.S. state. Unofficial results from Tuesday’s election showed Kemp leading by more than 60,000 votes and just over the 50 percent threshold he needs to avoid a runoff under Georgia state law.

Abrams’ campaign manager Lauren Groh-Wargo said there were thousands more mail, provisional and absentee ballots, however, still to be tallied.

The Democratic campaign cited an “incredible amount of irregularities” on Election Day, including rejected ballots and broken voting machines, and said it would consider all options including litigation to ensure a fair election.

The Georgia contest was among three dozen governor elections on Tuesday.

In some states, the races were seen as an early test of the parties’ strength ahead of the 2020 presidential race. Democrats seized seven Republican-held governorships, including in several states that helped deliver Republican President Donald Trump’s surprise win in 2016, without suffering any losses.

But Republicans triumphed in Florida and Ohio, both swing states that could play an outsized role in 2020.

In Florida, Democrat Andrew Gillum lost his attempt to become the state’s first black governor, suffering a narrow defeat to Republican Ron DeSantis in a racially charged contest.

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Republicans also scored a major victory in Ohio’s governor race, where Mike DeWine, the state attorney general, defeated Democrat Richard Cordray.

But in Wisconsin, Democrat Tony Evers appeared to pull off a narrow win to deny Republican incumbent Scott Walker a third term.

Democrats also won gubernatorial races in three other states - Michigan, Pennsylvania and Kansas - that supported Trump in 2016.

In Michigan, Democrat Gretchen Whitmer turned back Republican Bill Schuette, while in Kansas, Democrat Laura Kelly defeated Kris Kobach, a staunch Trump ally.

Democratic candidates also triumphed in Illinois, Maine, New Mexico and Nevada, where Republicans had held the governorships.

‘EVERY VOTE COUNTED’

The races in Florida and Georgia were seen as a test of whether liberal candidates could prevail in Southern states, where centrist Democrats have repeatedly lost, by appealing to a coalition of young and minority voters.

Both DeSantis and Kemp had strong support from Trump, who traveled to their states in the closing days of the campaigns to energize Republicans at “Make America Great Again” rallies. Democratic former President Barack Obama swooped in to boost the Democrats.

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Kemp, 55, oversees elections in his current role as secretary of state, a potential conflict of interest that drew repeated criticism from Democrats during the campaign. He refused to step down from his position and denied Democratic accusations that he used his office to suppress minority voters.

The fight for state power received less attention than the battle for control of the U.S. Congress but could have a major impact on issues such as congressional redistricting and healthcare.

Governors and hundreds of legislators elected this year will be in office when each state redraws congressional districts after the 2020 Census.

Going into Tuesday, Republicans controlled 33 governors’ mansions and two-thirds of state legislative chambers.

Democrats, playing catch-up after a net loss of 13 governorships and more than 900 state legislative seats during the eight-year Obama administration, fielded their largest slate of legislative candidates in more than three decades.

The party flipped six legislative chambers on Tuesday and now has complete control of state government in Colorado, New York, Illinois, Maine and New Mexico.

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