Former Georgia Lt. Gov. Geoff Duncan, who previously served as a Republican but shifted allegiances to become a Democrat last month, announced his candidacy for Georgia governor on Tuesday.

“Georgians need leaders with the bravery to challenge Donald Trump and act responsibly,” Duncan stated in his campaign announcement. “As the first Democratic governor in Georgia in nearly three decades, I will oppose Trump and his supporters in our state while working to reduce the costs of childcare, health care, and housing, ensuring every family in Georgia thrives. That’s what our state deserves.”

Although Duncan officially disconnected from the GOP recently, he has thrown his support behind Vice President Kamala Harris for president and participated in the Democratic Party’s nominating convention in August.

During his speech, Duncan highlighted Trump and his supporters’ efforts to challenge the 2020 presidential election results in Georgia, where Joe Biden secured the electoral votes.

“My path to this moment began years ago when I recognized Donald Trump’s willingness to deceive in order to overturn the 2020 election. Trump posed a direct threat to democracy, and his behavior disqualified him from ever returning to the Oval Office,” Duncan declared to Democrats in Chicago.

In January, the Georgia Republican Party’s State Executive Committee voted unanimously to expel Duncan, barring him from future involvement with the party.

In a video he released alongside his campaign launch Tuesday, Duncan referred to the GOP’s vote, telling viewers: “I’ve never wavered in taking on Trump. So Georgia Republicans threw me out of their party. I was leaving anyway.”

“Now I’m running for governor as a proud Democrat to focus on what matters most to Georgians,” he added.

The rest of the video focused on concerns about health care costs and rising prices, but Duncan also mentioned that he hopes “to make Georgia the front line of democracy and a backstop against extremism.”

Duncan is entering an already crowded Democratic primary field for governor, which includes former state Labor Commissioner and DeKalb County CEO Michael Thurmond, state Sen. Jason Esteves, state Rep. Derrick Jackson and former Atlanta Mayor Keisha Lance Bottoms.

On the other side of the aisle, state Attorney General Chris Carr and Lt. Gov. Burt Jones, Duncan’s successor, are running in the Republican primary.

Georgia, a longtime Republican stronghold, has emerged as a battleground state in recent years, and the governor’s race next year is expected to be one of the most competitive in the country. After Biden won the state narrowly in 2020, Trump won it last year.

While the state has two Democratic senators — including Jon Ossoff, who is up for re-election next year — Georgia has not elected a Democratic governor since 1998.