Here’s why a special election for a congressional seat in North Carolina matters, politically speaking: North Carolina Republicans have taken several blows over the past year, and losing this congressional seat would be big.

The seat is open because of an alleged election fraud scheme that benefited the Republican nominee in 2018. As a result, the election was nullified. Also, the state’s GOP chairman was indicted in April amid a campaign finance bribery scandal. Fresh off that scandal, Republicans now have to spend the better part of a year fighting for a congressional seat they’ve held for decades.

Republicans in the North Carolina 9th District just nominated state Sen. Dan Bishop, also known as lead sponsor of North Carolina’s controversial bathroom bill, for the position. Democrats stayed with their 2018 nominee, Dan McCready. Now the battle for the September election begins.

And it’s going to be a fight. Nonpartisan congressional analysts rate this seat as a toss-up even though the district voted for Trump by 11 points in 2016. But the planets need to align just right for Democrats to win here for the first time in decades, said Michael Bitzer, a North Carolina political expert and author of Old North State Politics blog. Here’s what it would take to swing the seat, according to experts:

Keep the spotlight on election fraud: What happened in this district was a pretty big deal. A campaign operative hired by the 2018 Republican nominee, Mark Harris, has been indicted on allegations that he tampered with absentee ballots to benefit Harris. Harris declined to run in 2018, which is why McCready will now face Bishop in September. Even though Bishop had nothing to do with this, Democrats don’t plan to let him cast his nomination as a fresh start for the party.

"The Republican brand and image has taken such a hit within the North Carolina 9th District lately,” said North Carolina Democratic Party official Robert Howard.

Generate enthusiasm — and then some: The blue wave in last year’s midterm elections helped 2018 Democratic nominee McCready, a Marine veteran, get within 900 votes of winning this suburban and rural district stretching along the South Carolina border from Charlotte. But it wasn’t close enough for him to actually win. So how can Democrats keep up the 2018 energy in an off-year, then raise it some, to elect McCready this time?

A national Democratic operative said that the sanctity of the vote could be a big motivator. But Democrats could have a hard sell given that whoever wins in September will have to run for reelection next November. “With 2020 around,” asked Bitzer, “is everybody going to be like, ‘Okay, it doesn’t matter who wins now?’ ”

Talk about the bathroom bill: Bishop led the fight for a 2016 controversial bill limiting which public restrooms transgender people can use.

“It is an anchor that will sink him,” Howard predicted. “It had already taken out a Republican governor in this state, and people here in this state are really embarrassed by the image it projected of North Carolina.”

Democrats say they also plan to make health care — particularly the issue of protections for preexisting conditions — an issue in the race. Talking about preexisting conditions in competitive races last year helped Democrats win the majority in the House of Representatives.

But Republicans point out that if Bishop is weakened by his legislative record, it didn’t show in Tuesday’s primary. He had a surprisingly strong performance, winning with 48 percent of the vote against nine other candidates. Republicans watching this race said it prompted them to reconsider how competitive Bishop could be.

Also helpful for Bishop is that at its core, this district is Republican. Part of Bishop’s state Senate district overlaps with the congressional boundaries. And when North Carolina’s Republican governor lost his seat in 2016 over the bathroom bill, this district actually supported that governor.

Try to separate McCready from national Democrats: McCready doesn’t have a legislative history that Republicans can whack him with. But the “D” next to his name on the ballot could be fault enough, Republicans say. Even though McCready said in the last election that he wouldn’t vote for Nancy Pelosi for House speaker, Republicans are going to try to use his background as a solar energy investor to tie him to liberal policies such as the Green New Deal championed by Rep. Alexandria Ocasio-Cortez (D-N.Y.), a liberal lightning rod for conservatives. Basically anything liberal lawmakers do in the House of Representatives over the next few months can and will be used against McCready.

It’s possible this district might be ready to elect a Democrat for the first time in decades, but everything has to go right for Democrats to do it.