Mr. Kennedy expressed his readiness to start working in Washington after winning New York’s special election to fill the congressional seat left vacant by Rep. Brian Higgins.
Mr. Kennedy, a State Senator, defeated Republican Gary Dickson for the upstate New York seat, benefiting from a 2-to-1 Democrat registration advantage in the district that includes Buffalo, Niagara Falls, and several suburbs.
He will serve in Congress for the remainder of the year, with a focus on reproductive rights, immigration, and stronger gun laws similar to those enacted in New York after a 2022 mass shooting at a Buffalo supermarket.
Nate McMurray, a former Grand Island town supervisor who planned to challenge Mr. Kennedy in a Democrat primary, was removed from the ballot due to insufficient signatures.
Mr. Kennedy announced his candidacy shortly after Mr. Higgins resigned from the seat in November 2023. He received endorsements from state and county leaders, including Sen. Sean Ryan.
Mr. Higgins, who left Congress in February, announced his resignation in November the previous year, citing frustration with the dysfunction in Washington.
During his time in Congress, Mr. Higgins played a key role in revitalizing Buffalo’s waterfront and was involved in various caucuses and task forces.
The Associated Press contributed to this report.