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.
"This is going to resonate so much more strongly...than the sort of more arcane policy-related issues that seem to coming up and causing a little bit of trouble for Hillary Clinton," he said.
"This is something more visceral, the videos are so much more in your face; clearly, painting Donald Trump in a worse and worse corner. It can't be good for him and any effort try and somehow compare what he has done to what Hillary Clinton has done in relation to Bill Clinton's scandals; it's just not going to wash."
Although Trump has previously said he had held off criticizing Clinton's husband, the former U.S. president, over his interactions with women, in the hours before the second presidential debate, at Missouri's Washington University, Trump took the gloves off. At a "debate prep" on Sunday night, Trump appeared with several women who have in the past accused Bill Clinton of sexual misconduct, in an attempt to turn the tables on his rival.
And during the debate, Trump told the audience that no one in politics had been "more abusive to women" than Bill Clinton. Clinton, who was president from 1993 to 2001, was impeached in 1998 by the House of Representatives in relation to his relationship with White House employee Monica Lewinsky.
Emory University's professor of political science, Andra Gillespie, told CNBC that Trump's strategy of claiming the Clintons were not in a moral position to criticize him had worked in the past, but may not continue to be effective at this late stage in the White House race.
"If Bill Clinton were on the ballot, maybe he would have had some traction, but it's Hillary Clinton who is on the ballot and she hasn't been accused of sexual misconduct and she is not the one who has made a stream of racist, misogynistic, anti-Muslim types of statements that fits the larger pattern that the tape that was revealed on Friday revealed," Gillespie told CNBC's "Squawk Box".