Former Sen. Kelly Ayotte announced Monday she will run for governor of New Hampshire, saying she doesn’t want the “Live Free or Die” state to turn into its liberal neighbor.

Ms. Ayotte, a Republican who served one term before losing a tight contest in 2016, jumped into the race after Republican Gov. Chris Sununu said he would not run for a fifth two-year term.

“I’m running for governor because New Hampshire is one election away from becoming Massachusetts — from becoming something we are not,” Ms. Ayotte, 55, said. “What we have here is worth fighting for. Together, we will ensure that New Hampshire remains safe, prosperous, and free.”

Ms. Ayotte promised not to implement an income or sales tax and said she would focus on reducing energy costs and “regulatory burdens” on residents and businesses.

She also pledged to support the police and crack down on violent criminals and fentanyl dealers.

Ms. Ayotte served as state attorney general before rising to national prominence as a U.S. senator during the last decade. She lost by a small margin in 2016 to Sen. Maggie Hassan, a Democrat.

Another Republican, former state Senate President Chuck Morse, said he would run for governor after Mr. Sununu this month said he would step down after his term.

Manchester Mayor Joyce Craig and Executive Councilor Cinde Warmington have launched bids on the Democratic side.

The Cook Political Report, a key elections tracker, is rating the election as a “toss-up” between the parties.

• Tom Howell Jr. can be reached at thowell@washingtontimes.com.