Republican presidential nominee Donald Trump speaks as his running mate Indiana Governor Mike Pence looks on. REUTERS/Mike Segar

After a 2005 video of Donald Trump making salacious comments about women surfaced on Friday, some prominent Republicans are calling on their nominee to drop out of the race.

That would launch a series of events unprecedented in a presidential race.

And it wasn't the first time conservatives have suggested Trump's resignation.

In August, the right-leaning Wall Street Journal editorial board published a scathing op-ed calling on Trump to mature his campaign style or hand the nomination to his running mate, Mike Pence.

But the scandals have continued. In the new, vulgar video, published by The Washington Post on Friday, Trump discussed trying to "f---" a married woman and wanting to kiss an actress he was about to appear with on "Days of Our Lives."

"And when you're a star they let you do it," Trump continued. "You can do anything. ... Grab them by the p---y. You can do anything."

Republicans all the way up to the chairman of the National Committee, Reince Priebus, condemned Trump for his comments. And then some started asking him to step aside. Top GOP Sen. Mark Kirk of Illinois said Trump "should drop out," and the RNC "should engage rules for emergency replacement."

"In a campaign cycle that has been nothing but a race to the bottom — at such a critical moment for our nation — and with so many who have tried to be respectful of a record primary vote, the time has come for Governor Pence to lead the ticket," former Utah Gov. Jon Huntsman told the Salt Lake Tribune a week after finally endorsing Trump.

Three-term Republican Governor of New York George Pataki tweeted: "[Trump's] campaign is a poisonous mix of bigotry and ignorance. Enough! He needs to step down."

A.J. Spiker, a former Iowa GOP chair and adviser to Sen. Rand Paul's PAC, said Trump was "unfit for public office." "Donald Trump should resign as the Republican nominee for president," he tweeted.

So what would happen in the extremely unlikely scenario that Trump quit the race? We took a look.

Can Trump give Pence the nomination?

Republican presidential candidate Donald Trump, right, and Indiana Governor Mike Pence, left, wave to the crowd at a campaign stop on July 12, 2016. Reuters/John Sommers II Whether Trump was hypothetically forced out or decided to drop out, a messy transition would ensue.

"I don't think he's going to step aside," Alex Keyssar, a political historian at Harvard University, told Business Insider in August.

But the fact that people are even suggesting that Trump should, Keyssar said, has never happened before at the presidential level.

"This is the first time any such discussion has really occurred," he said.

If Trump did decide to quit, Pence would not automatically receive the Republican nomination, Ballotpedia's Charles Aull, an expert on the presidential race and its many rules, told Business Insider in August.

The GOP would have to go through a formal process.

How could the GOP replace Trump?

The Republican National Committee's rules say it can fill any candidate vacancies that occur because of "death, declination, or otherwise" by either reconvening all 2,472 delegates to vote at another convention, or by letting its 168-member body decide via majority vote.

In the latter scenario, each member would get a certain number of votes based on the population of the state they represent.

Aull said this is much more likely, because reconvening another convention would be a logistical nightmare. And at this point, we've probably run out of time for another one, anyway.

Who would replace him?

If this happened, Aull said, choosing Pence would be the least controversial option (as opposed to former presidential nominees Gov. John Kasich or Sen. Ted Cruz), because he was already approved by Trump and chosen at the convention.

This choice could give some Republicans a sense of relief, Keyssar said, encouraging some voters who don't want to vote for the candidates from either party a reason to cast their ballots on Election Day instead of staying home.

Could the RNC say, 'You're Fired'?

A Texas delegate yells after the temporary chairman of the Republican National Convention rejected the efforts of anti-Trump forces. REUTERS/Jim Young A small subset of people have called for the RNC to use an extreme interpretation of the phrase "or otherwise" in the rules for replacing a candidate as a way to forcibly remove Trump from the nomination.

The RNC could also rewrite its rules to force him out, which would take even more time. That's pretty unlikely.

It could be the only way to get Trump off the ticket, though, since most presidential nominees don't simply drop out, Keyssar said.

"I think it's usually the case that you can assume that people who run for an office actually want to hold the office," he said. "They would not step aside, especially with the presidency. It's fulfilling their lifetime ambition."

If Trump didn't go willingly, he would probably sue the RNC if they use this "otherwise" clause and take the nomination away from him. Then it would be up to the courts to decide whom the nominee should be.

Since we're getting into serious hypotheticals here: If Trump, or any candidate, committed a major crime, he or she could still legally run for president. There's nothing in the US Constitution banning alleged felons from running for office. Socialist presidential candidate Eugene V. Debs even received one-million votes from behind bars in 1920.

If Trump, or whoever, were then convicted, the vice president might have to take over (if the new Republican nominee won the White House, that is). Or maybe he could pardon himself — we really don't have precedent for that ludicrous scenario.

Is it too late to get rid of Trump?

A formal re-selection process would take at least a couple weeks, and time is ticking down to Election Day on November 8.

Most states have their own ballot deadlines for presidential elections so people casting absentee ballots can vote for the correct candidates. We've flown past those.

Not only are the ballots locked in with Trump's name on the ticket, but early absentee voting has already started in several states, and several more will join in the coming days. The election is 31 days from Friday.

That means that if the RNC does replace Trump, his name would still appear on absentee ballots, and likely on the ballots voters cast in person on Election Day — not the new nominee selected by the party.

This could be incredibly confusing for voters who would want to vote for Pence, but would have to select Trump on the ballot, political scientist Josh Putnam told The Washington Post.

Several ballot deadlines have already passed, and more are coming up this week.

Another state-specific hurdle would come up after the election.

When voters select a candidate, they are really telling members of the Electoral College in their state to vote for that candidate. In some states, the electors can choose whomever they want for president. Others require they vote for a party based on popular vote. And in a third set, electors are legally bound to vote for the name on the ballot.

It's this third category where the Republican Party would have to go to court to transfer the votes for Trump to the replacement. That would be even more time consuming and "messy."

What if Trump steps aside the day after the election?

We have a Constitution for that one.

The 20th Amendment says: "If a President shall not have been chosen before the time fixed for the beginning of his term, or if the President elect shall have failed to qualify, then the Vice President elect shall act as President until a President shall have qualified."

In that case, Trump could effectively "choose" Pence to take over if the voters vote him into office and he then decides to step aside.

If any of that happens, could Pence win?

A screenshot of Google Trends during the vice presidential debate on October 4. Google Trends

During the vice presidential debate on Tuesday, Google traffic soared for people searching "Pence for president." And a poll Friday pegged him as the way-too-early frontrunner for the nomination.

Polls and pundits agreed the Republican vice presidential nominee won the debate, and cast Trump's ticket in a softer, more reasonable light. A poll on Wednesday even showed he was the 2020 frontrunner for president.

For some voters, Keyssar said, replacing Trump could be a bad idea. Most of his supporters are loyal to him and could feel betrayed by the RNC if it attempted to replace him with someone else.

But for others, Pence may be seen as their savior — particularly after a day like Trump had Friday.

"If there was a replacement nominee, it's still possible that that replacement nominee could win the election," Aull said in August. "Because so many of the issues that the GOP has been having have sort of centered on Trump himself ... it would probably generate some excitement. People are bound to be excited if somebody like Pence stepped in."

A previous version of this story ran August 18, 2016.