Geoff Duncan, a witness in Trump's Georgia case, has a warning for the GOP

Former Georgia Lt. Gov. Geoff Duncan, a Republican, says his party needs to cast former President Donald Trump aside if it ever wants to be competitive with Democrats again.

“Donald Trump sold a mirage to us,” Duncan told Yahoo News of the former president’s false election claims and his failure to build a border wall that would address Republicans' concerns about immigration.

“He has literally not built one single friend on the other side of the aisle and not built one single friend in the middle,” he added. “We watched that play out in Georgia. We lost Senate races multiple times.”

The former deputy of Georgia Republican Gov. Brian Kemp, Duncan on Monday testified before the Fulton County grand jury in District Attorney Fani Willis's investigation of Trump’s attempts to overturn the 2020 election in Georgia.

Later that evening, the former president and 18 co-defendants were indicted on racketeering charges stemming from their efforts to undermine President Biden’s victory.

Duncan and Trump at odds

Duncan has been one of the Republicans most outspoken about criticizing Trump's false election fraud claims.

“Best-case scenario is Donald Trump gets sworn in the White House with an ankle bracelet,” he said. “Worst-case scenario, he gets sworn in in cell block C.”

Trump, for his part, has slammed Duncan, calling him a “nasty disaster” early Monday for refusing to go along with his baseless claims that he won the election and for testifying before a grand jury.

Duncan, the author of GOP 2.0: How the 2020 Election Can Lead to a Better Way Forward for America’s Conservative Party, insists the party should focus on policy rather than catering to Trump.

“If we focus on the policies that we're really, really good at as Republicans, and we take that to the voters, I think we beat Joe Biden,” Duncan said.

In a Yahoo News interview series called "3 Questions," we asked Geoff Duncan about the state of the Republican Party and where Donald Trump fits within it. This interview has been edited for length and clarity.

1. Take me inside your grand jury testimony on Monday ahead of former President Trump’s indictment announcement. What can you tell me about the line of questioning you received?

I've been living this nightmare for two and a half years. You wake up a day after the election, you realize that the former president and his cohorts are trying to mislead millions and millions and millions of people. I would never have guessed in a million years it would've taken two and a half years to get to Monday’s indictment.

It was an unusual day, because sitting in that room with the grand jury, there was no doubt I was sitting in the center of the actual universe. Like, the whole world was going to care about what that room was about to decide. Of course, I didn't know which direction they were going, I just answered the questions.

It's like you're pitching the seventh game of the World Series, you're on the mound. You don't know what the outcome is going to be, but you know the world is watching that game. I was sitting in that room, and I knew the world cared about what was going to happen in that room.

2. You called Donald Trump the worst Republican candidate ever. Why has Trump earned this distinction? Is it more his character or impact?

It's all the above, and I meant every word of it.

I think what we've got to figure out is how Donald Trump is wired. There's nothing that he genuinely cares about around him. And I think a majority of Republicans — not an overwhelming majority, but a statistical majority — realize that. But then I think you have to dissect his four years in office, and shame on me for not being more critical earlier, even though I soured towards the tail end of that process.

We were pitched on “build the wall” for border security, but he didn't actually finish building the wall. It was a series of photo ops.

“Drain the swamp” was the greatest campaign slogan, literally ever. But does drain the swamp mean you literally add $8 trillion more to the national debt? Does drain the swamp mean that after your presidency, you realize there's all kinds of family deals going on, and special treatment? Does drain the swamp look like 91 indictments across four cases and federal indictments? That leads me to believe he didn't drain the swamp. He actually fed the swamp.

3. There were several Georgia Republicans named as part of the indictment, including David Shafer, the party chair. Yet GOP party leaders in the state like yourself, Gov. Kemp and Secretary of State Brad Raffensperger were all pushing back on Trump's claims, despite the state party chair endorsing those claims. Is the Republican Party fractured in Georgia, and how do you fix it?

The Republican Party, as an official organization in Georgia, is completely obsolete. In addition to Shafer supporting losing and rogue candidates, one of the biggest things that a state party does is create fundraising opportunities. They haven't raised enough money to shake a stick at in the past few years. If you want to screw it up as bad as you possibly can, as Republicans, go study what the Georgia GOP did over the last four or five years.

To change things around, both locally and nationally, you've got to have a three-part strategy: First, you've got to call out Donald Trump. There's no way, shape or form you can actually win this thing and beat him, if you don't call him out and tell him to sit down and shut up.

Secondly, you've got to have a game plan as to how to project to the rest of the world, to the rest of the country, “What's the plan to go forward? How are you going to actually do this?”

And three, Donald Trump's got to fall. He's got to fall under the weight of these indictments. The weight of reality is always right. It's just, how long does it take to be right?