CONCORD, N.H. (AP) — Democratic U.S. Rep. Annie Kuster of New Hampshire said Wednesday that she will not seek reelection to Congress for a seventh term in November, leaving the state’s sprawling 2nd District open to a possible GOP successor.

“I always said I was not going to stay in Congress forever,” Kuster, 67, said in a statement. She did not explain her decision.

Kuster is the longest-serving member in the history of the mostly rural district, which stretches from New Hampshire’s border with Canada to the Massachusetts line. It includes the cities of Nashua and Concord. The Democratic-leaning district hasn’t been in Republican hands since 2013, when the seat was held by Charlie Bass.

“I will continue serving the people of New Hampshire until the end of my term in January 2025,” Kuster said. “In the months ahead, I will use my time to help Congress build on the progress we have made and finish the job for the American people. I will continue to lead the New Democrat Coalition to help pass comprehensive, bipartisan legislation to move our country forward.”

Kuster, an attorney from Hopkinton, lost to Bass in her first run in 2010. Bass had held that seat for 12 years before getting ousted along with other Republicans nationally in 2006.

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Kuster, whose mother held a Republican seat in the state Legislature for 25 years, emphasized her ability to work with both parties. She defeated Bass in 2012 and was reelected five times. She defeated pro-Trump Republican Robert Burns, who runs a pharmaceutical quality control business, in 2022.

“It was certainly a safe seat for her,” said Dante Scala, a political science professor at the University of New Hampshire, adding Kuster was excellent at raising campaign funds.

Scala said Kuster built a reputation in Congress as a moderately liberal Democrat and centrist. Assuming there’s a competitive Democratic primary for the seat, it will be interesting to see if the nominee will be more left-leaning than Kuster.

Five Republicans have said they are running to be the party’s nominee for the seat.

“I still think it will be a significant lift for a Republican to win that district,” Scala said.

During the last election, Kuster championed her support of the Inflation Reduction Act, which requires Medicare to negotiate lower prices with drug companies. The legislation included Kuster’s bill to eliminate out-of-pocket vaccine costs for seniors and Medicare beneficiaries.

She also sponsored the legislation to award the Congressional Gold Medal to members of the top-secret World War II Ghost Army 75 years after their service.

Kuster was founder and co-chair of the Bipartisan Addiction and Mental Health Task Force. She was founder and co-chair of the Bipartisan Task Force to End Sexual Violence.

“As I look to the future, I am excited by the work and opportunities that lie ahead. We all have a role to play in standing up for what we believe in, advocating for a better future, and pursuing the change that we want to see,” she said.

Kuster has spoken about her post-traumatic stress from being trapped in the House gallery as rioters tried to beat down the doors on Jan. 6, 2021. The insurrection interrupted the certification of President Joe Biden’s victory. Kuster calls herself a “survivor, witness, victim of the insurrection on Jan. 6 in our Capitol.”

Her colleague in Congress, First District U.S. Rep. Chris Pappas, called her " a trailblazer and a respected leader who always puts the needs of Granite Staters first.

“I know that her work fighting for important priorities is far from over, whether that’s continuing bipartisan collaboration to address addiction and mental health, standing up for reproductive freedom, or safeguarding our democracy,” the Democrat said.