Democrat’s U-Turn to Join the G.O.P. Upends North Carolina Politics

The startling defection of a longtime Democratic lawmaker upended the balance of power in North Carolina on Wednesday, giving Republicans narrow veto-proof supermajorities in both chambers of the battleground state’s legislature.

The Democratic lawmaker, State Representative Tricia Cotham, announced in a news conference on Wednesday morning that she was becoming a Republican, saying she had been bullied by her fellow Democrats and had grown alienated from the party on issues like school choice.

“The modern-day Democratic Party has become unrecognizable to me and to so many others throughout this state and this country,” she said in a brief speech. She said both she and her young children had been subjected to personal attacks by Democrats in the state, and denounced what she called attempts to “control” her. “They have pushed me out,” she said.

Her declaration infuriated fellow Democrats and sent shock waves through North Carolina. A reliable Democratic vote when she served in the House from 2007 to 2017, she once stood on the House floor and shared her experience of having an abortion, calling it “a deeply personal decision” and accusing Republican lawmakers of “wanting to play doctor.”

Ms. Cotham, 44, whose district sits outside Charlotte, ran again successfully for the chamber in November on a platform of raising the minimum wage, protecting voting rights and bolstering L.B.G.T.Q. rights.

Now, however, her decision helps Republicans cement razor-thin but complete control over a second chamber of the legislature, giving them the ability to bypass Gov. Roy Cooper, a Democrat, and create a glide path for their legislative agenda. Republican leaders have indicated a desire to seek new restrictions on abortion and tighten the state’s voting laws, among other issues.