Atlanta (CNN) Rev. Raphael Warnock crouched forward in a back pew here at Ebenezer Baptist Church and wondered what could have been.

"I'm not afraid of Johnny Isakson," said Warnock of his Republican senator, at times distracted by the decades-old, muffled recordings of Martin Luther King Jr.'s sermons that echoed in this historic sanctuary. "I'm not interested in a symbolic candidacy. I would've run to win."

A few hours later, the Democrat who is challenging Isakson instead of him, Jim Barksdale, tried to evince that same optimism speaking to a group of supporters at a Tex-Mex restaurant in Gwinnett County.

"This is a winnable election. Don't let anyone tell you anything else," said Barksdale, a 63-year-old soft-spoken investment manager and political newcomer. "I wouldn't be in it if I didn't think it was winnable."

Barksdale, however, trails Isakson by 16 points in a Monmouth University poll released Monday , even though Donald Trump is up only 3 points ahead of Hillary Clinton. Georgia is looking increasingly like a missed opportunity for Democrats trying to win back the Senate -- and many fault Barksdale himself.

"We were giving a godsend, I believe, with Donald Trump," said Barksdale supporter Leonard Ware as he waited for the candidate to speak in Gwinnett. "If we had a stronger candidate, we could've taken that Senate seat."

For national Democrats, Barksdale's disappointing bid is part of a broader trend facing the party that came into 2016 with a favorable map of Senate races.

In Ohio, Ted Strickland has been hampered by repeated gaffes and fundraising woes that have led national Democrats to essentially abandon a once-top candidate in the homestretch. Democrats have begun to make similar moves in Florida, where Patrick Murphy -- once a young, impressive recruit poised to flip a GOP seat -- has suffered dearly for embellishing his background and given Republican opposition researchers a trove of material.

And here in Georgia, a half-dozen prominent Democrats passed on challenging Isakson, a decision that some in the party now rue.

Even with the tight presidential race, Barksdale isn't trying to capitalize on any anti-Trump sentiment in Georgia. He didn't mention the GOP presidential candidate when meeting supporters campaigning Friday and barely addressed it until CNN asked him about the top of the ticket in an interview.

That's a far cry from the Democratic playbook that has proved to be moderately successful in other Senate races. Democrats have tortured GOP incumbents like Ron Johnson in Wisconsin and Richard Burr in North Carolina for their embrace of the nominee, and the poll numbers show it.

Part of his reticence is that Barksdale, a former Bernie Sanders-backer, says he believes there are issues where he agrees with Trump. And he predicted a slew of Barksdale-Trump voters this November.

"It's hard to imagine how somebody can pull the lever for Donald Trump on the Republican side -- who is so anti-the-establishment and anti-the-trade-things -- and then pull the lever for Johnny Isakson," Barksdale said.

African-American gap

Georgia Democrats have long seen their political viability as resting on the state's booming minority population, and Barksdale's campaign agrees. If he can consolidate the black vote and win 85% of the community's 2.1 million voters, Barksdale aides say, he can win.

The problem, revealed in a walk along this city's historically African-American Sweet Auburn neighborhood: People don't know who he is.

"Black dude?" asked Paul Jones, a registered Democrat sitting on a ledge outside an abandoned park here, asked about the white Barksdale. "Oh, no, I don't know him."

Some here do know Isakson, and he is a revered figure in some pockets of Georgia's middle class. At a major Republican call center in Isakson's home base of Cobb County last week, nearly everyone calling on his behalf have some personal relationship with the two-term senator -- whether they teach his granddaughter at Sunday school or write to his personal email every few weeks.

And a trio of prominent Democrats, former US Sen. Sam Nunn, former Gov. Roy Barnes, and current US Rep. David Scott have all publicly backed Isakson, snubbing their own nominee.

Despite Trump's struggles -- especially among independent women in the suburbs -- Isakson's team is calm and confident, thanks primarily to the caliber of the man they are facing.

Their main concern is how much Barksdale himself plans to invest his campaign. He has invested $3 million so far, and he declined repeated questions about how high that total would go.

"No question that our Democratic friends are kicking themselves, given how volatile the electorate has become, for not having recruited a candidate with a higher profile with a better set of policies and messages," said Heath Garrett, Isakson's chief strategist said at their campaign office.

"The flip is -- they have a candidate that's willing to write a check," added campaign manager Trey Kilpatrick.

Man in the hat

Aside from not going after Trump, Barksdale has had other missteps that have cost him.

The list of grievances among Georgians against Barksdale is long: the time conservative radio ridiculed him for misspelling 'judgment' on his campaign website; his sparse public event and interview schedule, stripping him of needed exposure; and his inability to effectively consolidate the Democratic base.

Barksdale is further to the left than the centrist Senate bid waged by Michelle Nunn in 2014, who was thought to be a good ideological fit for Georgia despite being walloped in an open-seat contest.

His calling card -- the cotton Bailey flat caps that he wears each day -- has drawn criticism as well from Georgia power brokers.

"I get a lot of compliments on it," he said. "Everybody was worried that it wouldn't appeal within the, let's call it, minority communities -- but it really does."

The cap has emerged as the signature emblem of Barksdale's laggard campaign, with one soft-focus television ad featuring Georgians securing his cap over their hair ("Could I give you a good look here?" he told one grade-schooler here before revealing his balding head.) His office in littered in cap imagery, with supporters imploring Republicans to "send the hat" -- not Barksdale, or as some call him more forgivingly, "the man in the hat" -- to the Senate.

National Republicans don't send trackers to his events and have barely advertised against him as well.

Republicans concede that Isakson would have faced a stronger test if Atlanta mayor Kasim Reed, or rising star state Rep. Stacey Abrams, or presidential scion Jason Carter, had not so strongly resisted overtures from party leadership to run a race seen as winnable.

"I had conversations with folks who were thoughtful about their request, and I was speedy in my response," said Abrams as she awaited a flight. "I was very unequivocal about the fact that I had no interest in running for the Senate."

"I thought seriously about it and I came this close to running," said Warnock, who said he wanted to remain at his church. "This was not my time."

Several Democrats pointed to trends that explained Democrats' candidate problems nationally -- poor showings in 2014 sapped ambition from some red-state hopefuls, while others made their decisions well before Trump's struggles. Democrats did not land their first-choice recruit in North Carolina, and others have not lived up to the hype that came with their entrances into the race.

"When you look at states like North Carolina, Missouri and Indiana -- which were places that no one thought were going to be competitive this time last year -- I think it speaks to the quality of the candidates that came forward," said DSCC spokesman Lauren Passalacqua, who would only characterize Georgia as "another area that we think is competitive in a year when Republican have struggled."

Isakson, for his part, takes some credit for the Democrats' A-team declining to challenge him. "I've made a lot of friends. And I try to represent all the people when I'm in office," he said in an interview. "I'm grateful they decided to stay where their careers were."

Run-off in January?

The biggest challenge for Isakson at this point is getting to 50% -- the number he needs to avoid a run-off in January. The Monmouth poll has him at exactly that mark -- with a margin of error of 4.9 percentage points.

Isakson aides predict a runoff would cost each side more than $20 million, and it could become a national spectacle should control of the Senate hang in the balance.

"If Johnny gets into a general election runoff, there will be money from all over the country that's going to pour into Georgia," said Eric Tanenblatt, a longtime Republican fundraiser and power player here in the state. "If Hillary Clinton were to win the White House, does she come down here to campaign for Barksdale?"

But that may be the Democrats' best hope at this point.

"I was not the likeliest candidate," Barksdale said. "If anyone else had gotten involved that I thought I was credible, I would've certainly let them carry the water instead of me."