If Republicans are to win in increasingly blue Northern Virginia, analysts say, their best shot might be a candidate like former delegate Joe T. May — a moderate who lost his Loudoun County seat in 2013 after conservative Republicans accused him of being out of step with their agenda.

May, who briefly left the GOP the next year, is now the Republicans’ hope in a Jan. 8 special election to replace state Sen. Jennifer T. Wexton (D-Loudoun), who is heading to Congress. It’s a contest that pits him against progressive Democrat Del. Jennifer B. Boysko (D-Fairfax County) in an area near Dulles International Airport that has been held by Democrats since 2006.

Voter turnout is not expected to be strong for an election held just after the holidays in the 33rd Senate District, which counts traffic congestion, school funding and affordable health care as its chief concerns.

But the outcome could point the way forward for both parties in suburban battlegrounds as they gear up for statewide elections in 2019 that may determine control of the General Assembly, analysts say.

May — an architect of Virginia’s $3.5 billion transportation funding law in 2013 who served 20 years in the House of Delegates — reflects his state party’s attempts to regroup after a decade of statewide losses and a blue wave that nearly wiped out its majority in the legislature. In November, the party was further weighed down by its candidate for U.S. Senate, Corey A. Stewart. He lost that election to Sen. Tim Kaine (D-Va.).

Boysko — who earlier this year passed legislation requiring companies to avoid using animals while testing cosmetics or household cleaners — represents an emboldened progressive Democratic Party base that is looking to push deeper into Virginia’s historically conservative exurbs.

“This is in many ways a perfect test case,” said Quentin Kidd, director of Christopher Newport University’s Wason Center for Public Policy in Newport News.

“How progressive can Democrats be with their candidate in a district that otherwise isn’t pretty far left?” Kidd said. “And, how moderate do Republicans have to be with their candidate in order to start winning again in those areas?”

Straddling the borders of Fairfax and Loudoun counties, the 33rd District — represented by Attorney General Mark R. Herring (D) before Wexton took over in 2014 — has favored Democrats in recent elections.

In November, the district picked Kaine over Stewart by 41 points, while playing an instrumental role in Wexton’s 12-point overall win against Republican Rep. Barbara Comstock, according to the Virginia Public Access Project, a nonprofit organization.

In 2017, Gov. Ralph Northam (D) beat Ed Gillespie (R) there by 35 points. And in the 2016 presidential contest, Hillary Clinton took the district by 30 points over Donald Trump.

May, 81, saw the shift to the left as a chance for political redemption.

In 2013, the electrical engineer who served nine terms representing Loudoun, fell victim to his party’s then-surging tea party movement, losing a primary election challenge to Del. David A. LaRock (R) that focused on voter anger over the tax increases that came with the transportation law.

The next year, May ran as an independent in the special election against Wexton and Republican John C. Whitbeck to fill the Senate seat after Herring became attorney general. But with Whitbeck — who went on to become state Republican Party chair — gaining most of his party’s support, May won just 9 percent of the vote.

In the current election, May is highlighting his former pariah status, calling it proof of his record as an independent-minded legislator.

Along with pledges to focus on traffic congestion and find more state funding for STEM education programs, May has adopted positions that might seem foreign to some Republicans.

Among them: supporting Virginia’s ratification of a federal Equal Rights Amendment, lauding the state’s Medicaid expansion law, and calling for more background checks for gun owners.

“I’m trying to strike what I think are the appropriate positions,” May said in an interview. “I’m in the happy position where I don’t have to have the political office. Do I wish it? Certainly. But it won’t be the end of my career if I’m not successful with it.”

Boysko, 52, is also tilting toward the political center, though she says the district is now more in line with progressive goals such as Medicaid expansion.

In an interview, she emphasized her efforts to deal with transportation problems in her mostly Fairfax district, saying she joined a fight to limit Interstate 66 tolls during morning and evening rush hours.

“I know transportation backwards and forwards,” Boysko said. “I understand what my community wants because I’ve been at their doors talking to them, listening to them and advocating for them.”

On a recent rainy weekend morning in Leesburg, just a handful of volunteers showed up to help May get out the vote, mostly by phone because of the weather.

“His decisions are well reasoned,” said Pat Daly, 67, explaining why she decided to pitch in. “And, he knows how things work in Richmond.”

About 12 miles away in Sterling, Boysko hosted a more energetic get-out-the-vote rally, with at least 75 volunteers — including Wexton and several other Democratic officials — eager to keep the Senate seat in Democrats’ hands.

“This is not going to be an easy race,” Wexton warned the group as they prepared to head out into the rain to knock on doors. “People are exhausted. People are not really paying attention, everybody else out there kind of thinks that we’re done. And, her opponent is someone who is pretty well known in the region.”

Stephen J. Farnsworth, a political science professor at the University of Mary Washington in Fredericksburg, said that might have been enough for May in years past, particularly after a transportation funding law that has led to several local road improvements.

But the drag on the state party caused by the president’s unpopularity and Stewart’s controversial Senate run means that May has a steeper hill to climb, Farnsworth said.

“Obviously, Joe May is not a Corey Stewart Republican,” he said. “But the level of anger in Northern Virginia about the Trump presidency means that the ‘R’ after your name is a significant barrier, regardless of what kind of Republican you are. It’s just not a friendly environment for Republicans.”