Nellis, who was a senior adviser to former Vice President Kamala Harris's 2024 presidential campaign, appeared alongside Newsmax contributor Mary Walter.
Sadler, a former special assistant to Trump, left the White House in 2018 after she dismissed opposition to a CIA nominee from the late Sen. John McCain (R-AZ) because he was "dying anyway," The Hill reported.
" Kamala Harris is claiming Republicans are cheating by making sure noncitizens aren't on the voter rolls," Sadler said as she opened the segment.
"They are cheating by purging voter rolls," Harris said in a clip the network then played.
Sadler cited a recent Reuters report that found about 30,000 noncitizens on the nation's voter rolls since 2000. But the former Trump aide didn't tell her Newsmax audience that Reuters said those registrations were the result of software glitches, found no evidence that the people had cast any votes and that, if they had, the number was "too small relative to the country’s more than 170 million registered voters to impact elections."
"Well, according to official records reviewed by Reuters, U.S. states may have added more than 30,000 self-declared noncitizens to the nation's voter rolls since 2000 because of software glitches and clerical errors made while processing their driver's license and state ID applications. This sounds like a problem," Sadler told viewers after the clip.
"They're taking away the one last perk we have as citizens, which is the right to vote, and they're giving it to anyone who just happens to be sitting their butt here," Walter said.
"Well, nobody's taking away your right to vote. I think that's hyperbole, and it's another example of Republicans trying to undermine our democracy because they know they're gonna lose in November," Nellis replied.
"Even the framing of this conversation was you saying Kamala Harris is saying it's wrong to remove people who are noncitizens from the rolls," Nellis told Sadler.
"She's talking about how Republicans are trying to rig the game in the middle of the election," he said of Harris.
"Donald Trump is actively trying to federalize our elections right now and have the federal government take it over," Nellis continued. "There was a CNN report today that Trump's outside advisers are encouraging him to declare martial law so that he can take over the elections."
"Ultimately, Republicans can't win this election in November without cheating," Nellis said.
"And this 30,000 votes… excuse me, these 30,000 noncitizens that were added to the rolls, it was a glitch in the system," he added.
Sadler cut in without responding to Nellis's points.
"Well, we actually are gonna have to cut from this segment to go to New Jersey, where Gov. Mikie Sherrill is holding a news conference," Sadler said as Nellis finished. "She had a big problem with the illegals on her voter rolls. Let's take a listen."
However, Sherrill (D-NJ) had called the news conference to announce that she had named Acting State Comptroller Shirley Emehelu to serve as acting secretary of state, not to address "illegals" on the voter rolls.
According to another Reuters analysis published earlier this year, federal prosecutors have charged only 129 people under a federal "voting by aliens" statute Congress created in 1996.
The outside advisers Nellis described have been urging Trump to seize control of federal elections this fall, The Atlantic reported Wednesday.
"Either martial law, or step aside," attorney Peter Ticktin, who attended military school with Trump, told The Atlantic of the choices he believes Trump could face around Election Day.
A White House official told The Atlantic that Ticktin and two other outside advisers play no role in election policy at the White House.
