Even before U.S. President Donald Trump was sworn into office in January, his opponents had been discussing a particular section of the U.S. Constitution they believe would be their best bet at ousting him.

Now that he occupies the Oval Office, the topic of the 25th Amendment and how it could be used to end Trump’s presidency, remains a hot topic among so-called “Never Trumpers.” The Atlantic’s senior editor David Frum and GQ Magazine’s special correspondent Keith Olbermann have made repeated appeals on social media, for example, espousing the prospect of using the 25th Amendment.

Under Section 4 of the 25th Amendment, the president can be removed from office if “unable to discharge the powers and duties of his office.”

Gary Nordlinger, a professor at George Washington University’s Graduate School of Political Management, told CTV’s Your Morning on Tuesday, how it could be invoked to remove a president: if the vice president and the majority of cabinet deem the president unfit for office, they notify the House of Representatives and Senate and the vice president will take over as acting president.

But, while that sounds simple, it’s not.

Nordlinger said, at any time, the president can petition to be restored to the presidency. If the vice president and the majority of cabinet reject the president’s appeal, then another vote is taken. In order to remove the president permanently, a two-thirds majority is required in both the House and the Senate.

To put this in perspective, a president can also be removed from office through impeachment. To impeach a president, a simple majority of the House and two thirds of the Senate is required, as opposed to the two-thirds majority needed in both the House and the Senate under Section 4 of the 25th Amendment.

“Elvis Presley has a better chance of being found alive than President Trump being removed by the 25th Amendment,” Nordlinger said. “It’s easier to impeach the president.”

So why are Trump’s critics still talking about this section of the constitution as a feasible option? Nordlinger said they’re just desperately looking for loopholes, like they did when Trump first won the Republican Party nomination and they wanted to change the rules of the convention or when he was elected and they hoped the Electoral College would vote against him.

“This is just grabbing at straws but it makes for great conversations,” Nordlinger said.

Nordlinger said Section 4 of the 25th Amendment has been used in the past, but as a temporary measure when a president needed medical attention. He pointed to the example of when former president George W. Bush underwent a couple of colonoscopies and his vice president, Dick Cheney, became the acting president for a few hours.

The professor added that it’s highly unlikely Trump’s vice president and cabinet would even want to remove him from the presidency in the first place. Nordlinger said the Republican Party has controlled the White House for 36 years out of the 64 years since former president Dwight D. Eisenhower was sworn into office in 1953. He said of those 36 years, the Republicans have only controlled both the House and the Senate for six of those years.

“They want to get things done,” Nordlinger said. “They don’t want to be removing Trump.”