Republicans are sharpening their attacks on each other even as they scramble to block Democrat Jon Ossoff from scoring an upset victory with one week to go until the nationally watched special election to represent a suburban Atlanta district in Congress.

The all-out scramble is taking place in all corners of the 6th District, which stretches from east Cobb County to north DeKalb County. And as the Republicans in the race compete for what could be one runoff spot against Ossoff, national GOP groups are trying to undermine his campaign.

Ossoff is facing a new wave of attacks from conservative groups hoping to avert an embarrassing defeat in the most competitive race since Donald Trump’s election as president. The district, last held by Tom Price before he was tapped to be Trump’s health secretary, has been in GOP hands since Jimmy Carter’s presidency.

Millions of dollars have poured in from conservative groups outside the district to ensure it stays that way, including $3 million from a group with ties to U.S. House Speaker Paul Ryan that has hired nearly 100 field staffers and funded a blitz of attack ads.

The Democrat has plenty of ammunition to fight back. He raised more than $8.3 million, largely from out-of-state donors frustrated with Trump, as Ossoff has turned into a symbol of the resistance to the president. He collected checks from nearly 200,000 donors, for an average of less than $50 per contributor.

He’s also taken advantage of the deep divisions that have riven the 11 Republicans on the April 18 ballot. They’re increasingly clashing in public over policy, including sharp disagreements over health care proposals and loyalty to Trump.

But the more visible battles are raging on the airwaves, on computer screens and in mailboxes and voicemail boxes across the district. Much of it is aimed at a trio of leading GOP contenders all competing for the same slice of the electorate: Karen Handel, Bob Gray and Dan Moody.

Democrats, meanwhile, are increasingly hopeful that Ossoff can achieve what was once considered unthinkable: winning the race outright. He’s already spent $6 million boosting his campaign, and he’s likely to pump much of the rest of his campaign cash — more than $2 million remains in his account — in a final push.

And Democrats are hoping Ossoff, who has emerged as the unquestioned leader in a field that includes four other Democrats, will benefit from the campaign muddle. All 18 candidates will share the same ballot, regardless of party, and a June 20 runoff awaits the top two vote-getters if no candidate gets a majority.

“There are way too many candidates in the race,” sighed Brian Bonser, a Dunwoody Republican who is split between three or four GOP contenders. “I normally tune out the negative ads, but this is frustrating. And what’s worse is the phone calls.”

More: In Georgia special election, Republicans fight Ossoff - and each other