Calls by some Republicans to replace Donald Trump at the top of the GOP ballot are not realistic, a politics pro told CNBC, as another called Trump's decision to double-down his attacks on rival Hillary Clinton misguided.
After a recording emerged of the Republican presidential candidate making crude comments about women, Republican senators including John McCain pulled their support from Trump, as did prominent party members. Some went as far as calling for vice presidential nominee Mike Pence or another candidate to replace the mogul at the top of the GOP ballot.
According to NBC News, the Republican Party's leaders could pick a replacement if a nominee withdrew - something Trump is adamant he will not do - but NBC pointed out that at least 34 U.S. states offered early voting and several only allowed voting by mail, which meant Trump ballots had already been printed and sent to voters.
Bates Gill, a professor at the Australian National University, told CNBC's "The Rundown" on Monday the fact that votes had already been cast meant that replacing Trump as the GOP's presidential candidate was "legally speaking ... nearly impossible."
"Much of the voting has already been done, the absentee voters have already voted for Donald Trump or others ... You can't rescind those votes at this point," Gill said.
"I don't even think the Republican National Committee rules would allow something like that other than [when in] the actual demise, the passing, of the individual at the top of the ticket. I think under the current circumstances it's impossible," he added.
The latest scandal will hurt Trump's chances with undecided voters, Gill said.