Mike Cryans and Joe Kenney were locked in a dead heat Tuesday night to fill the Executive Council District 1 seat left vacant when longtime Executive Councilor Ray Burton died last year.
Late results appeared to show Republican former state Sen. Kenney in a close race against Cryans, a Democratic Grafton County commissioner.
"We're going to see how things shape up. But we're feeling optimistic," Kenney said about 10 p.m.
In a statement released at 11 p.m., Cryans said his campaign would wait until all results were in.
"I want to thank Joe Kenney for a hard fought race, everyone who came out to vote or volunteered on either of our campaigns, and the Burton family for their support. We always knew this would be a challenging race, a Democrat has not occupied this seat in at least my lifetime. We are waiting for the last several towns to report their results, and ensure that every voter is heard."
"Congratulations to all the Granite Staters who exercised their right to vote today," state Democratic Party Chairman Ray Buckley said in a statement. "New Hampshire is known for close elections and tonight's is certainly one of them."
Kenney said the campaign featured a lot of driving during the dead of winter in the state's geographically largest Executive Council district, which encompasses the entire northern half of the state.
"It was a lot of tough roads ... but it was a good campaign," Kenney said.
For the first time since 1981, someone other than Burton will occupy the seat, which he rarely left unfilled while recording a nearly perfect attendance record during his decades on the Executive Council.
Burton won for the first time in 1976, then lost in a primary to Paul Mayette in 1978, before reclaiming the seat in 1980 and keeping it until his death last November.
Cryans received several key endorsements during the race, including from Gov. Maggie Hassan and members of Burton's family. Kenney also received his share of endorsements, including from the state's top Republican, U.S. Sen. Kelly Ayotte.