U.S. Senate candidate Doug Jones (D) chats with constituents before a Democratic Senate candidate forum at the Princess Theatre in Decatur, Ala. on Aug. 3, 2017. (Jeronimo Nisa/Decatur Daily/AP)

The victory of former judge Roy Moore in Alabama’s Republican Senate primary gives Democrats a choice — whether to actually compete for the seat vacated by Attorney General Jeff Sessions.

Democrats have not seriously contested an Alabama Senate race since 1996, but they think they have a credible candidate in Doug Jones, a former U.S. attorney who successfully prosecuted members of the Ku Klux Klan who bombed a black church in Birmingham in 1963, killing four girls. Several progressive groups think they have a clearer shot at winning the general election in December than they would have if Sen. Luther Strange, the establishment candidate who lost resoundingly to Moore on Tuesday, had won.

Clearer, but not necessarily easier.

After a string of high-profile defeats in special House elections, two of them in the Deep South, Democrats are approaching the Jones campaign carefully. The 63-year-old lawyer, who has never run for office, has raised less than $300,000 despite securing the Democratic nomination a month ago. Moore raised more than $1.4 million but was outspent by Strange. Alabama, which gave a 28-point victory to President Trump last year, has not elected any Democrat to statewide office this decade.

In an interview conducted before Moore secured his win, Jones said he had a unique opportunity to break Democrats out of their rut. He would offer “political checks and balances” on the Trump administration, reach out to independents and provide a sober contrast with firebrand Moore.

Controversial conservative and former Alabama chief justice Roy Moore won the Republican primary for the state's Senate seat on Sept. 26, setting up a crisis within the GOP. Here's a look at three problems his win poses for the D.C. establishment. (Jenny Starrs/The Washington Post)

“Roy Moore’s taken social stands that are completely out of step with Alabama,” Jones said. “And the Republican Party has just completely destroyed the public’s confidence in its leadership. This is the least transparent, least ethical group we’ve seen in Montgomery for a generation.”

It may help Jones that national Republicans opposed Moore, too. Through PACs and allies, they dumped millions of dollars into anti-Moore ads in the run-up to Tuesday’s election, portraying him as a corrupt political lifer who enriched himself from his own charity. Now, the GOP must rally around a nominee who has twice been suspended from his job as Alabama chief justice for disobeying federal court orders with which he disagreed on religious grounds.

“I’ve never seen a clearer contrast between candidates,” said Democratic National Committee Chairman Tom Perez. “Roy Moore is unfit to serve; all you have to do is ask Mitch McConnell about that. Moderate Republicans are just as offended as Democrats that Roy Moore might wind up in the Senate.”

Still, the scale of Moore’s victory Tuesday — he beat Strange by nearly 10 points — is a cautionary note. As of Tuesday night, Democrats agreed with Jones’s pitch but were still weighing whether it was worth investing in his race. The Democratic Senatorial Campaign Committee, tasked with defending 10 incumbent senators in states won by Trump last year, has monitored the Jones race and advised on staffing — but has not yet committed resources to the race.

“Doug Jones is a fantastic candidate,” DSCC Chairman Sen. Chris Van Hollen (D-Md.) told reporters on Tuesday. “He has a real shot.”

The DNC has done a bit more for Jones, sharing the latest voter file with his campaign and helping him add staff after the primary. Former vice president Joe Biden, who has known Jones since the 1990s and encouraged him to make a run, recorded a robo-call for his primary bid and plans to return to Alabama on Oct. 3 to stump for him. American Bridge, a progressive opposition research group, prepared a 21-page memo of research to help Jones and other Democrats target Moore.

Doug Jones, a candidate in the Democratic primary for Alabama's open U.S. Senate seat, criticized the president's response to violence in Charlottesville on Aug. 15. (The Washington Post)

But Democrats, who hope to make Moore an embarrassment for national Republicans, have little idea whether the race can be competitive. They remain cautious about plowing into Alabama and allowing Moore to present the campaign as a purely partisan contest.

Republican polling has found everything from a close Moore-Jones race to a looming Moore landslide. On Tuesday, Republican pollster Whit Ayres told CNBC that Moore’s victory might well “put the seat in play.” There has been no independent Democratic polling.

Artur Davis, a four-term Democratic congressman from Alabama who briefly switched to the Republican Party, said Jones would struggle to distinguish himself from a Democratic brand that has become toxic in Alabama.

“The early polling for Doug sounds good, but in the two or three polls I have seen, he is still stuck at the 38-40 percent Democratic base, no higher,” Davis said. “To pull the 20 percent of Republicans he needs, he is going to have to make this a race about common-sense ideas, working with both sides, and avoid the temptation to portray this race as a clash of dark and light. That will backfire here quicker than Roy can say Jesus.”

For Jones to win, Democrats believe he must achieve three difficult tasks. He needs strong black turnout; his civil rights record, well-known in the state, is considered an asset. He will need as much as 30 percent of the white vote — a stiff challenge in a state where Democratic presidential candidates now get about 10 percent of that vote. And he needs to be the beneficiary of a unique Dec. 12 election that could present a turnout challenge.

Progressive groups, intrigued by the stark choices and tricky electoral math, are increasingly interested in the race.

Daily Kos, a progressive blog that has crowdsourced millions of dollars in donations to other special-election candidates, will decide in October whether to back Jones. On Sept. 21, MoveOn.org endorsed Jones after 98 percent of its Alabama-based members urged it to do so.

“National Democrats should follow Jones’s lead and vigorously contest congressional seats in all parts of the country,” said Matt Blizek, director of election mobilization for MoveOn.org.

Some of the progressive energy around Jones is left over from the spring, when activists denounced Democratic campaign groups for helping special-election candidates in Kansas and Montana only after Republican PACs had poured money into those states to attack them.

“I believe the Democrats should compete in every state in this country,” said Sen. Bernie Sanders (I-Vt.), the only national figure who stumped for the party’s nominees in those states.

But more of the enthusiasm was rooted in Jones himself, a civil rights lawyer whose low-key campaign so far has been defiantly progressive. Jones opposes the Hyde Amendment, which prevents any federal funding for abortion; while stopping short of endorsing Sanders’s “Medicare for All” bill, he supported the Democratic effort to save the Affordable Care Act, and criticized Alabama for declining to expand Medicaid. In an interview, he said he would have voted against Betsy DeVos’s nomination to be secretary of education, and might have opposed Neil M. Gorsuch’s nomination to the Supreme Court.

“People don’t want a lap dog for Mitch McConnell, but they don’t want an attack dog, either,” Jones said. “Unfortunately, Jeff Sessions’s voice is what people think of when they imagine the typical Southern politician. And that’s not true. There’s a lot of folks on the other side who might be concerned about the rollback of civil rights we could see under Jeff Sessions at the Justice Department.”

On Tuesday night, as news of Moore’s victory spread, Jones’s progressive following grew. His Twitter account, created at the start of the campaign, quickly surged from 8,000 to around 15,000 followers; writers at progressive outlets pointed to him as a uniquely well-positioned opponent to Moore, an ideologue who has suggested that homosexual activity should be illegal and that the United States might have been attacked on Sept. 11, 2001, because “we legitimize abortion.”

In the spring and summer, Republicans managed to define Democratic candidates before those candidates could get traction in special elections. In Montana, they exposed folk singer Rob Quist’s past problems with taxes and unpaid bills; in Georgia, they hammered Jon Ossoff relentlessly for living a few miles outside of the suburban district in which he was running.

Jones, an Alabama native who became famous for the church bombing case, had fewer obvious vulnerabilities than those of other hopefuls. Ossoff, a first-time candidate who raised more than $30 million for his four-point defeat, said that Jones could define himself and ignore criticism if donors outside of Alabama began pouring in to help.

“Humble advice: Balance your criticism of this incompetent president with your own positive vision beyond reaction and opposition,” Ossoff said. “If partisan hacks funded by a few corrupt billionaires and lobbyists attack you for raising small dollars from ordinary Americans, you’re doing it right.”