It was no surprise that powerful business boosters backed Republican Sen. Johnny Isakson's reelection bid on Monday. The subtext, though, was that they're willing to pump big money into a relatively sleepy campaign.

Georgia was long seen as a safe seat for the two-term incumbent, who has high name recognition, broad support among Georgia Republicans and more than $5.7 million in the bank. But the tandem of Donald Trump and a self-financing millionaire Democratic opponent could scramble the race.

Trump's divisive candidacy could swell turnout from Democrats – and prod some Republicans disillusioned with his campaign to stay home. Isakson gave Trump his full-throated endorsement last week in Cleveland, but has maintained that his top focus is on his re-election battle.

Complicating matters for Isakson's camp is the unorthodox campaign of Democrat Jim Barksdale. The investment manager has largely run a stealth campaign with few public events, and the political newcomer remains relatively unknown to many voters and even some Democratic insiders.

But he's already pumped more than $3 million of his own fortune into his campaign, while raising less than $100,000. And his low profile could work to his advantage as he works to cast himself as a Democratic outsider – albeit one who can stroke another check at any moment to blanket the airwaves.

That's where Monday's announcement plays in. The Georgia Chamber and the U.S. Chamber of Commerce both formally endorsed Isakson's campaign, no shock for groups that typically back conservatives. But they also left the implicit message that, should the race tighten, they'll pour money into the contest.

“We are all in for his re-election, 1,000 percent,” said Rob Engstrom, the national political director for the U.S. Chamber and a Georgia native who was on hand for the announcement.

Added Chris Clark, the Georgia Chamber’s head: “We are going to do whatever it takes to win this election.”

Isakson, for his part, said Monday the campaign was expecting Barksdale to dig deeper into his wallet.

“He’s demonstrated he’s willing to write a giant check, and I’m sure there are probably more giant checks to come,” he said, adding: “I believe you earn your way through, you don’t buy your way through. This race ought to be about the issues, not the amount of money you have.”