McKoon said the party’s state executive committee will consider a measure to permanently ban Duncan from qualifying as a Republican for any state office. The Republican National Committee will consider a similar request from McKoon regarding running for national office.

Duncan has not publicly indicated he plans on running again for office.

The Georgia GOP also plans to adopt a resolution condemning Duncan’s “self-serving and hypocritical behavior” that formally expels him from the party, although Georgians don’t register by party anyway. And McKoon said Duncan will be “treated as a trespasser” if he seeks to attend any Georgia GOP event.

“Consequently, you are not and never will be considered a Republican ever again,” McKoon wrote. “I request that you govern yourself accordingly.”

Duncan and Trump-backing Republicans have long been at odds, even during his single term as Georgia’s lieutenant governor. But McKoon’s letter marks a significant escalation.

Credit: Seeger Gray/AJC

Credit: Seeger Gray/AJC

Duncan dismissed the attack as political pandering from someone who has “decided to lick the boots of Donald Trump, a man who spent most of his life registered as a Democrat, donating to Democrats and supporting Democratic candidates.”

And he mocked McKoon for devoting more than $1.7 million to help pay the legal fees for several of Trump’s codefendants in the Fulton County racketeering case - and for McKoon’s short-lived bid for Secretary of State in 2018.

“I sleep soundly every night comfortable with not only my conservative credentials,” Duncan wrote, “but also the knowledge that I don’t wake up every day hoping I won’t have to defend the indefensible conduct of a morally bankrupt man who couldn’t pick you out of a police lineup, even if he tried.”

A schism

McKoon’s letter came after Duncan cemented a schism with the party over the former president’s comeback bid.

Once a Trump supporter, the former state legislator won an upset election in 2018 to become Georgia’s No. 2 politician by defeating a better-known candidate in a GOP runoff.

He quickly emerged as a contrarian within the party and an outspoken critic of Trump after the then-president sought to overturn his defeat in the 2020 election. Duncan also opposed initiatives by Trump’s allies to restrict no-excuse absentee voting and set other limits on ballot access.

Duncan decided against running for a second term in 2022, when he would have faced a Trump-backed Republican rival, saying he would work to promote his vision of a “GOP 2.0″ instead that moves beyond divisive rhetoric.

But he still maintained a role in politics. He refused to endorse Herschel Walker, the Trump-backed U.S. Senate nominee in 2022, and he also wouldn’t support the campaign of Burt Jones, who went on to succeed him as lieutenant governor. Both were Trump loyalists.

Duncan was a key witness in the Fulton County election interference investigation against Trump and his allies, testifying before a grand jury shortly before District Attorney Fani Willis announced indictments against the former president and 18 co-defendants.

Credit: Arvin Temkar/AJC

Credit: Arvin Temkar/AJC

He also retained a political megaphone through social media and stints as a CNN commentator and Atlanta Journal-Constitution contributor.

Earlier this year, Duncan met with key donors and leaders of the No Labels movement to weigh a possible third-party presidential bid. But he passed on a run in March, telling the AJC the “math got too personally difficult.”

Duncan headlined a pro-Biden event in Atlanta along with another Republican, former U.S. Rep. Adam Kinzinger, shortly before a June 27 debate. But he expressed sharp concerns about Biden’s viability after his abysmal performance in the showdown against Trump.

Shortly after Biden ended his campaign, Duncan joined Democrats who were quickly uniting behind Harris’ bid. He told “Politically Georgia” that he had misgivings with the vice president’s policies but he would back her because she was the “only vehicle” to beat Trump.

And he spoke glowingly of Democratic enthusiasm behind Harris after attending her downtown Atlanta rally this week, saying the crowd of roughly 10,000 attendees reminded him of a “national championship” game.

“If Donald Trump thinks he is going to steamroll his way back to the White House, he has another thing coming,” Duncan told the AJC. “This race is still about the 10% in the middle, and my money is on Harris getting their attention better than Donald Trump.”

McKoon’s letter to Duncan began with the kind of nasty personal attacks increasingly common in partisan wars in recent years.

“In a life otherwise devoid of accomplishment (e.g. dropping out of college, failing as a minor league baseball player, starting a series of sketchy businesses), your nominations by the Republican Party were signal honors, without which you would have never served as a member of the Georgia General Assembly or the Lieutenant Governor of this Great State.

“You repaid this debt of gratitude with a single, largely self embarrassing term in office as Lieutenant Governor.”

Many of Trump’s Georgia allies cheered McKoon’s letter, while others suggested Duncan wasn’t worth the effort. Jones, his successor, this week brought up Duncan’s background as a pitcher in the Miami Marlins’ minor-league system to hammer his political shift.

“He was a minor leaguer then. He’s a minor leaguer now,” Jones said. “Everything Duncan does is amateur hour.”

Read the entire letter: