Georgia Republican Johnny Isakson has won re-election to the U.S. Senate, holding off two challengers.

Around 10 p.m. Tuesday, Isakson said Democrat challenger Jim Barksdale had just called him to concede the race and congratulate him on the victory, which Isakson said was a class act.

"God bless him, I wish him the best of luck," Isakson told cheering supporters at the Georgia Republic Party's election-night gathering in Atlanta.

Georgia Gov. Nathan Deal said the state "proved once again that we believe in conservative representation in the United States Senate."

Isakson had relied on a series of television ads focused on his Senate work, largely avoiding references to the presidential campaign. Though he was expected to win, Isakson sometimes struggled to draw a line between himself and Donald Trump while maintaining support for the party's divisive presidential nominee. The 71-year-old also dealt with questions about his health. He has Parkinson's disease.

Democrats in Georgia hoped Trump's low popularity with some voters could hurt Isakson's re-election campaign. But the party's candidate — Barksdale — struggled to get momentum against the well-known Isakson.

Barksdale is a newcomer to state politics and ran a low-key campaign until early October when he ramped up criticism of Isakson's continued endorsement of Trump. But unofficial results suggest the shift was too little, too late.

Barksdale's best chance was to force Isakson into a nine-week runoff election. State law requires a candidate to reach more than 50 percent of the vote to avoid a runoff.

Isakson has never failed to close out a Senate contest in November. He won about 58 percent of the vote in his last two Senate campaigns, winning over independent and Democratic voters swayed by his reputation as a moderate willing to work across party lines.

Early results suggest this year's margin will be narrower.

Isakson's supporters gathered Tuesday evening at the state party's event at a hotel in the Atlanta's Buckhead neighborhood. Isakson was smiling and joking with friends at the hotel early Tuesday evening before going into an upstairs room to watch vote returns on a laptop computer with his campaign staff.

Barksdale was expected to join other Georgia Democrats at a hotel in downtown Atlanta. Party Chairman DuBose Porter rallied the crowd early in the evening, urging them to keep an eye on counties in metro Atlanta that tend to report later in the evening.

Barksdale was attending the Democratic Party of Georgia's election night party across town, at the Hyatt Regency Hotel in downtown Atlanta, his campaign staff said. His supporters were hoping he could garner enough votes to force Isakson into a runoff.

Chris Hamer, 48, voted for Libertarian Gary Johnson for president because he said he has no confidence in either Trump or Democrat Hillary Clinton, but he shunned the Libertarian senate candidate in favor of Isakson.

"I can't really complain about the job he's been doing," said Hamer, after voting at a church in Sandy Springs. "For the state, he's been good."

Karen Taylor, 52, also voted at a Sandy Springs church and cast her presidential vote for Clinton. Her vote for Barksdale was motivated more by party need rather than a strong feeling of support for him, she said.

"If I want Clinton to win, then I need the Senate to be Democratic as well so she can get things done," she said.