Georgia’s GOP lieutenant governor recently described U.S. Senate hopeful Herschel Walker as "one of the worst Republican candidates in our party’s history." 

Lt. Gov. Geoff Duncan explained to CBS News why he chose not to vote for Walker ahead of Tuesday’s runoff election, where the Republican challenger faces off against Democratic Sen. Raphael Warnock. 

"I’m a conservative. I’m a conservative because I think it’s the best way to govern. I’ve been a Republican a lot longer than a lot of folks. I think I’ve got kids probably that could articulate the conservative platform better than some of the candidates that Donald Trump and his group supported all across the country," Duncan told CBS News congressional correspondent Nikole Killion last week. 

"This wasn’t the right brand for Republicanism, and I think Herschel Walker will probably go down as one of the worst Republican candidates in our party's history," Duncan said in the on-camera interview.  

GEORGIA BREAKS EARLY VOTING RECORD AS WALKER, WARNOCK RUNOFF SEES OVER QUARTER MILLION TURNOUT IN SINGLE DAY

Herschel Walker at campaign rally

Republican candidate for U.S. Senate Herschel Walker speaks during a campaign rally Tuesday, Nov. 29, 2022, in Greensboro, Ga.  ( AP Photo/John Bazemore)

For at least the past two years, Duncan has been a very vocal GOP critic of former President Donald Trump

Duncan, along with recently re-elected Gov. Brian Kemp and Secretary of State Brad Raffensperger, pushed back against the then-president when Trump urged them to overturn the 2020 presidential election results in Georgia. 

Duncan is also the out-going lieutenant governor. Partially due to his opposition to Trump, he decided long ago not to run for re-election as lieutenant governor this year. Trump-backed Burt Jones, a state senator, won election as lieutenant governor last month and will succeed Duncan in January.  

Georgia saw record-breaking early voting turnout ahead of the Dec. 6 runoff. Early voting ended Friday. 

Walker, endorsed by Trump and Texas Sen. Ted Cruz, has been accused of prior domestic abuse by his ex-wife and also faces allegations he paid for two women to have abortions. 

Warnock and Obama

Former President Barack Obama, left, greets Sen. Raphael Warnock, D-Ga., right, before Obama speaks during a rally on Thursday, Dec. 1, 2022, in Atlanta.  (AP Photo/Brynn Anderson)

Former President Barack Obama, at an Atlanta rally for Warnock on Thursday, criticized Walker for a peculiar stump speech in which the Republican discussed a movie about vampires and werewolves. 

Walker had made comparisons to the movie’s message about the importance of faith – and not holy water or a cross alone – protecting people from a vampire’s attack. 

"It is time for us to have faith. We’ve got to have faith in our fellow brother. We’ve gotta have faith in this country. We’ve gotta have faith in elected officials," Walker told supporters. "And right now, that’s the reason I’m here. Because God has brought his warrior. And I’m that warrior that y'all have been looking for for a long time. I can promise you as my offensive lineman told me, ‘Herschel, follow me. I’ll take you to the promised land. And I’m gonna tell y’all right now, if you vote for me, I’m gonna have us all get to the promised land."

Herschel Walker smiles with supporters

Republican candidate for U.S. Senate Herschel Walker takes photos with supporters during a campaign rally Tuesday, Nov. 29, 2022, in Greensboro, Ga. Walker is in a runoff election with incumbent Democratic Sen. Raphael Warnock.  (AP Photo/John Bazemore)

Obama sarcastically noted Walker’s discussion of "issues of great importance to the people of Georgia," which include "what is better to be a vampire." "I talk about what a good football player he is, but I also have [to realize] that I did not think he had either the confidence or the character, the track record of service that would justify him representing Georgia in the United States Senate right now," Obama said. 

Speaking at a Boston fundraising event over the weekend, President Biden said Walker "does not deserve to be in the United States Senate based on his veracity and what he said and what he hadn’t said."

"The other man is a really, truly decent honorable guy," Biden added of Warnock. 

CLICK TO GET THE FOX NEWS APP

The final race in the upper chamber of the U.S. Congress to hang in the balance post-midterms, Senate control is no longer at play, with Democrats already having secured 50 seats to go with Vice President Kamala Harris’s tiebreaking vote. The race between Warnock and Walker will determine if Democrats can expand their majority or if Republicans will maintain the 50-50 balance.

Fox News' Paul Steinhauser contributed to this report.