ATLANTA – The country’s attention will turn to Georgia today, where voters in suburban Atlanta will decide the outcome of a bitterly fought race with national implications.

Even the president is paying attention.

“The Dems want to stop tax cuts, good healthcare and Border Security,” President Donald Trump tweeted Monday morning. “Their ObamaCare is dead with 100% increases in (premiums). Vote now for Karen H.”

Trump is referring to Karen Handel, the former Georgia Secretary of State who is locked in a tight race with Jon Ossoff – a Democrat who has mounted an unlikely challenge in this once reliably red district.

The contest to replace now-Secretary of Health and Human Services Tom Price is the most expensive U.S. House race in history, a distinction that reflects what’s on the line for both parties.

One advocacy group, the nonpartisan Issue One, estimates that as much as $59.6 million has been poured into the race since it began earlier this year.

Issue One estimates that nearly half of the money dumped into the race has been controlled by outsider groups, such as the political action committee behind an attack ad tying Ossoff and Democrats to the Alexandria shooting that left a Republican congressman in critical condition.

The ad, paid for by the Principled PAC, calls on voters to stop the “unhinged left.” Handel condemned the ad.

As for the candidates, Ossoff has easily raised more money than Handel. He reported taking in more than $23 million while Handel raised more than $4 million, according to the Federal Election Commission.

Polls show that District 6 voters, though, appear evenly split. The most recent polling data gives Ossoff a slight edge in a district that sent Newt Gingrich to Washington and that re-elected Price in November.

Trump only won the district by 1.5 points. That lukewarm support for Trump is what has, in part, caused some to eye this special election as a possible early referendum on Trump’s presidency.

Ossoff has tried to tap into some of the anti-Trump mood, launching his campaign with a call to “Make Trump Furious.”

Democrats also hope they can capitalize on the public’s wariness toward a Republican plan to replace the Affordable Care Act.

A recent poll by the Atlanta Journal-Constitution revealed only one-quarter of District 6 voters said they favored the House’s new plan. About 81 percent said they considered health care policy to be extremely or very important.

Handel supports the Republican plan that cleared the House last month. Ossoff, a 30-year-old investigative filmmaker, has said the current law can be improved and that he’s opposed to a repeal.

Other issues, such as climate change, have further highlighted the stark differences between the candidates. Handel supports Trump’s decision to leave the Paris Climate Accord. Ossoff has said “history will condemn us” for doing so.

Already, more than 140,000 voters have cast a ballot in the run-off, according to the Secretary of State’s Office. That’s double the number of people who voted early in April, when Ossoff nearly won the race outright.

Republicans have since consolidated support behind Handel, and several national party figures – including Vice President Mike Pence – have made stops in Atlanta to campaign for her.

Trump also held a fundraiser for Handel while in town for the National Rifle Association’s annual meeting in April. He expressed relief at the time. “Let’s not have 11 Republicans running for the same position, OK? It’s too nerve shattering,” he said.

Jill Nolin covers the Georgia Statehouse for CNHI’s newspapers and websites. Reach her at jnolin@cnhi.com.