Democratic Senate candidate Cal Cunningham has been leading North Carolina polls for months, but an October surprise may give an opening to incumbent Sen. Thom Tillis, R-N.C.

Cunningham, who is married, admitted to exchanging romantic texts with California woman Arlene Guzman Todd after the messages leaked. Guzman Todd later told The Associated Press that they had a physical affair.

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Tillis’ campaign has hammered Cunningham for scaling back public events to avoid questions after the revelation.

“This is my third event today. I’ve invited press to every one of them,” Tillis told reporters on Friday. “The best I can tell, he hasn’t had a discussion with the press by his own choice for nearly a month. This race is very important, the issues are very important, and I would invite him to come out and maybe debate or at least answer hard questions that you all should ask.”

Democratic challenger Cal Cunningham, left, and U.S. Sen. Thom Tillis, R-N.C. greet each other after a televised debate Thursday, Oct. 1, 2020, in Raleigh, N.C. (AP Photo/Gerry Broome, Pool)

Meanwhile, the race has national attention as Republicans and Democrats battle for control of the Senate — a fight that could be decided by North Carolina voters.

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“Clearly, our Senate race is the big one. For a while in the summer, it looked like Cunningham might be running away with this thing,” elections policy analyst Andy Jackson of the conservative Civitas Institute told Fox News. “He is trying to basically survive and hope that the early momentum will be enough to keep his head above water.”

So who is Cal Cunningham? Here are three things to know.

1. He is a lawyer and businessman

Cunningham is a lawyer and businessman who recently served on Democratic Gov. Roy Cooper's Crime Commission looking at solutions to the opioid epidemic and school gun violence, his campaign said.

Democratic challenger Cal Cunningham speaks during a televised debate with U.S. Sen. Thom Tillis, R-N.C. Thursday, Oct. 1, 2020, in Raleigh, N.C. (AP Photo/Gerry Broome, Pool)

The 47-year-old was born in Lexington, N.C., and earned his undergrad and law degrees from the well-respected University of North Carolina-Chapel Hill.

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Cunningham does not currently hold office, although he briefly served in the North Carolina State Senate in the early 2000s. Elected at 27, he was one of the youngest North Carolina state senators.

2. He serves in the military

Cunningham is also a lieutenant colonel in the Army Reserve. He joined the military after 9/11 and has served overseas in Iraq and Afghanistan. However, the U.S. Army Reserve said it is investigating Cunningham shortly after Guzman Todd, a military wife, said she engaged in an extramarital affair with the politician as recently as July.

In this Monday, Jan. 27, 2020, file photo, Democratic U.S. Senate candidate Cal Cunningham speaks during an interview in Raleigh, N.C. (AP Photo/Gerry Broome, File)

3.    His campaign is hammering Tillis on health care

Cunningham’s campaign and North Carolina Democrats have focused on health care in the final days of the race, painting Tillis as the candidate who wants to remove protections for North Carolinians with preexisting conditions.

“President Trump and Senate Republicans have made clear time and time again they have no health care plan. He and Senator Tillis have no plan on how to protect the nearly 5 million North Carolinians with a pre-existing condition,” North Carolina Democratic Party Chairman Wayne Goodwin said in a statement after Tillis voted to confirm Supreme Court Justice Amy Coney Barrett.

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Despite the scandalous headlines, the Democratic Senatorial Campaign Committee is sticking with Cunningham. The DSCC confirmed to Fox News in October that it added an additional $3 million to its ad buy for the final two weeks of Cunningham's bid against Tillis. 

More than $280 million has been spent on the Cunningham-Tillis race, making it the most expensive Senate race in U.S. history.

Fox News’ Paul Steinhauser and the Associated Press contributed to this report.