While many Americans may have been stunned by Sunday's news that President Biden had decided to drop out of the 2024 campaign and endorse Vice President Kamala Harris to replace him at the top of the ticket, some Republicans had quietly prepared for that moment.

In fact, they are already preparing to spend millions on lawsuits in key swing states where they believe local election laws forbid swapping out Biden for another Democrat.

In an appearance just hours before Biden announced he was exiting the race, House Speaker Mike Johnson of Louisiana told ABC News that doing so "would be wrong, and I think unlawful, in accordance to some of these states' rules for a handful of people to go in a back room and switch it out because they're, they don't like the candidate any longer."

“That's not how this is supposed to work,” he added. “So I think they would run into some legal impediments in at least a few of these jurisdictions."

The Heritage Foundation, one of the conservative groups that crafted Project 2025, the blueprint that would restructure government agencies and dismantle environmental regulations should Republicans retake control of the White House, drafted a memo in June that asserted that the laws in some states do not allow for removing a candidate from ballots for reasons other than death.

“There is the potential for preelection litigation in some states that would make the process difficult and perhaps unsuccessful,” the memo stated, though most election experts expressed doubt that legal challenges from Republicans will hold up in court.

Mike Howell, the executive director of the Heritage Foundation's Oversight Project, told Newsweek that the group has set aside millions of dollars for the coming legal fights.

"I think there'll be a compelling case to be made that that shouldn't happen, and so I think they've got legal trouble,” Howell said.

All eyes on swing states

Elections in the United States are overseen by individual states, and each one has its own set of laws concerning a candidate’s eligibility requirements.

Wisconsin election law, for instance, is quite explicit on the subject of replacing a candidate after they’ve been selected to appear on a ballot.

"Any person who files nomination papers and qualifies to appear on the ballot cannot withdraw their name from the ballot after filing. The name of that person shall appear upon the ballot except in case of death of the person," the law states.

For that reason, Wisconsin is seen as one of a handful of states where Republicans plan to file a challenge against Democrats replacing Biden. Two other swing states, Georgia and Nevada, are also on that list.

"Three of the expected six most contested states have some potential for preelection litigation aimed at exasperating, with legitimate concerns for election integrity, the withdrawal process for a presidential candidate," a memo shared with Newsweek by Howell read.

Legal experts say the challenges won’t be successful

There’s a simple reason most legal experts believe that the Republican lawsuits have little chance of success: Biden has not yet received his party’s presidential nomination.

During the Democratic primary, Biden earned roughly 99% of his party’s pledged delegates thanks, in part, to the fact that he didn’t face any serious opposition. While those delegates had pledged to vote for Biden at the Democratic convention, they were not legally required to do so under party rules and are unlikely to do so now that Biden has dropped out of the race.

Last week the Democratic National Committee backed off its plan to hold a virtual vote that would have secured the nomination for Biden ahead of the convention. As a result, the party is still without a nominee.

"The Democratic Party did not have an official nominee yesterday, and the same can be said today," David Becker, a former Justice Department attorney and election law expert, told CNN. "Until the delegates vote, Democratic Party rules state that there is no official Democratic nominee. There was no one to be 'replaced' on the ballot because there is nothing to replace yet."

Marc Elias, a voting rights attorney who has successfully argued several cases for Democrats stemming from the 2020 election, also threw cold water on the Republican lawsuits.

"Before the media gets rolling, let me be clear: The Democratic nominee for president will be on all 50 state ballots," Elias wrote Sunday in a post on X. "There is no basis for any legal challenge. Period."

Richard Hansen, a professor and the director of UCLA Law's Safeguarding Democracy Project, agrees that the legal challenges were likely to fail and that "in the unlikely event that a state law would make Biden be forced to be listed on the ballot — I'm not even sure how that could be — then I expect litigation would place the actual nominee of the party on the ballot."

‘The coup is complete’

For many Republicans who saw fit to question the outcome of the 2020 election, the idea that Democrats could, at this late stage, replace Biden with another candidate has been hard to swallow.

"This is outrageous. The media has a responsibility to push back and say, wait a minute, you don't get to dump this [president] — this is what happens in other countries, not in America," Ric Grenell, who served as acting director of national intelligence under Trump, said at an event during last week's Republican National Convention.

Sen. Tom Cotton of Arkansas, who also had a speaking slot at the convention, went even further.

"Joe Biden succumbed to a coup by Nancy Pelosi, Barack Obama and Hollywood donors, ignoring millions of Democratic primary votes," Cotton wrote on X.

Many other Republicans, however, have demanded that Biden resign as president now rather than try to serve out the remainder of his term, including Sen. JD Vance, Trump’s running mate.

“If Joe Biden ends his reelection campaign, how can he justify remaining President?” Vance said in a post on X on Sunday.

In his statement announcing his exit from the race, Biden said that he would “focus solely on fulfilling my duties as President for the remainder of my term."

As for the man who lost to Biden in 2020 and is likely to go up against the person the Democratic delegates pick to replace him, the latest developments are being seen as just the latest injustice.

"They stole the race from Biden after he won it in the primaries — A First! These people are the real THREAT TO DEMOCRACY!" former President Donald Trump wrote on Truth Social.