(Danny Johnston/AP Photo)

After three weeks off, the primary season continues today. Voters go to the polls for run-offs in Alabama and North Carolina, with three races where voters will cast ballots.

No incumbents face the chopping block tonight, but there is one race where an incumbent's backing could determine the race. All three look like they will go to the GOP, so in two of tonight's run-offs, the primary results could determine the winner in November. There is likely to be low turn-out in all three races so we could see some surprises.

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Here are the three races to watch today:

AN INCUMBENT'S BACKING: In the GOP run-off for North Carolina's sixth congressional district, Rockingham County District attorney Phil Berger Jr. is facing off against Baptist minister Mark Walker to replace the retiring Rep. Howard Coble, R-N.C. In the initial primary for the Greensboro seat, Coble stayed neutral, but in the run-off the 83-year-old has backed Berger. WHY IT MATTERS: The 15-term Republican has stumped alongside Berger during the run-off, appearing at campaign events, fundraisers, on mailers, and even recording a robocall. Berger - the son of a state Senate leader - bested Walker in the primary, but he did not cross the 40 percent threshold to avoid a run-off. Having that support, as well as more campaign cash, and Coble's backing could mean victory today. But with low turn-out and Walker being the pastor of a large congregation, nothing is certain. The winner of what turned into quite a contentious primary will face off against former University of North Carolina system administrator Laura Fjeld in November. The Republican is favored in this race so the winner tonight will likely also be the November victor.

THE OTHERS:

GOP RUN-OFF FOR ALABAMA'S SIXTH CONGRESSIONAL DISTRICT: Conservative activist Gary Palmer and Alabama State Rep. Paul DeMarco are facing off in this run-off to succeed retiring GOP Rep. Spencer Bachus. It's another heavily Republican district, making tonight's winner the likely November victor as well. Palmer has the support of the anti-tax group Club for Growth in the run-off since its first choice did not make it through the initial primary, but DeMarco bested Palmer in the primary, as well as in fundraising, and has the backing of the NRA. The Club has dumped about $250,000 in the race and its support could help shift the tide towards Palmer in this re-match. Palmer also has strong ties to the religious community in the district, which could help in what is expected to be a low-turnout run-off. The district is one of the strongest Republican House districts in the entire country, meaning Democrat Avery Vise has little chance at victory.

DEMOCRATIC RUN-OFF FOR NORTH CAROLINA'S FIFTH CONGRESSIONAL DISTRICT: Software developer Josh Brannon is up against former State Department employee and former candidate for Winston-Salem mayor, Gardenia Henley. The winner will face five-term incumbent Rep. Virginia Foxx, R-N.C. Brannon bested Henley in the primary, but did not cross the 40 percent threshold needed to avoid a run-off. This district in the northwestern part of the state is heavily Republican so it's likely tonight's winner won't impact Foxx's November re-election.

ABC News' Caleb Jackson contributed to this report.