Even if a Democrat emerges as the top vote-getter in Georgia’s special congressional election Tuesday, the race is almost certain to go to a runoff, where Republican strategists said they will prevail and notch another win for President Trump.
Democrat Jon Ossoff, a former congressional aide and first-time candidate, is leading the polls but would have to win more than 50 percent of the vote to claim outright victory.
That is unlikely in a field of nearly 20 candidates, and Republicans are hoping that in a one-on-one matchup they can close the gap before a June 20 runoff.
“If Ossoff doesn’t put this away Tuesday, he is not going to win,” said Jay Williams, a Georgia-based Republican Party strategist. “If it gets to a runoff, the Republican will win.”
Liberal pressure groups have nationalized the race in the state’s 6th Congressional District — a seat made open by the appointment of Rep. Tom Price as Health and Human Services secretary. They believe that putting Mr. Ossoff over the top would be a rejection of the Trump agenda and could scare Republicans from aggressive moves.
“A Republican loss here would send a bitter rebuke to the entire Republican Party that Americans across the country do not support their radical, anti-worker agenda,” said Kaitlin Sweeney, spokeswoman for the Progressive Change Campaign Committee.
Eleven Republicans are running for the seat in an increasingly nasty race for second place and the chance to face Mr. Ossoff.
Polls suggest the contest within the contest has boiled down to a battle between former Secretary of State Karen Handel, who has the support of former Sen. Saxby Chambliss; former state Sen. Dan Moody, who has the backing of Sen. David Perdue; state Sen. Judson Hill, who has the support of former House Speaker Newt Gingrich and Sen. Marco Rubio of Florida; and Johns Creek City Council member Bob Gray, who has the support of the Club for Growth.
Mrs. Handel has taken the most arrows. Mr. Moody, Mr. Gray and Mr. Hill, as well as and the anti-tax Club for Growth, have attacked her, casting her as a self-interested career politician.
In the meantime, a group called Ending Spending, which is funded by the Ricketts family, owner of the Chicago Cubs, is running pro-Handel ads.
“It is like a circular firing squad with Republicans,” said David Johnson, another Georgia-based Republican Party consultant. “I think if Republicans had united behind Karen Handel or Moody or Judson Hill, I don’t think there would be a race at this point.”
Mr. Williams said the infighting could haunt Republicans on Tuesday by pushing Mr. Ossoff over the finish line.
“If the Republicans keep beating themselves up as much as they have, it might suppress our own voters from showing up,” he said. “And if he can keep the intensity up among his supporters, he can get there.”
While the Republican Party is divided, liberals have managed to coalesce around Mr. Ossoff, feeding the hope of Democrats eager to land a body blow against Mr. Trump since he stunned progressives by defeating Hillary Clinton last year.
The “resistance” movement missed an opportunity to score an upset last week in the special election in Kansas, but progressives took solace in the fact that Republican Ron Estes won by 7 percentage points in a district that Mr. Trump won by 27 points six months ago.
Mr. Estes cautioned against seeing that race as a bellwether, and analysts said it had its own factors, including an unpopular Gov. Sam Brownback dragging down Republicans in the state.
Geoffrey Skelley, of the University of Virginia’s Center for Politics, also warned against viewing the Georgia election as a sign of things to come.
“The Georgia 6th contest should be viewed as just one part of trying to gauge the future political atmosphere,” Mr. Skelley said, adding that Democrats might be making a play for an unwinnable seat.
“Democrats should probably be careful not to become overinvested in the Georgia 6th outcome. We’re talking about a district that routinely re-elected then-Rep. Tom Price with at least 60 percent of the vote for years and that Mitt Romney won by 23 points,” he said.
“Yes, President Trump struggled there comparatively, winning by 1.5 points, but it’s still a district with a Republican registration advantage,” he said.