A prominent Donald Trump supporter has criticized Republicans for pushing Democrats to replace Joe Biden as the party's presidential nominee, arguing that those efforts could make the 2024 election more difficult for the GOP.

Conservative commentator Rob Smith—who recently switched his party affiliation to independent, but signaled he would still vote for Trump in a Newsweek op-ed published last month—issued a warning to Republicans as calls for Biden's withdrawal from the race reached new levels in the aftermath of last month's presidential debate.

"Republicans - being the idiots they are - are playing into the plan to replace Biden with a younger, fitter, fresher candidate that has a much better chance at mopping the floor with Trump in November. Fools," conservative commentator Rob Smith wrote on X, formerly Twitter, Sunday.

Biden's CNN debate performance reignited questions about his age and ability to serve a second term, with even Democrats raising questions about whether the 81-year-old should still be the party's nominee with just four months until Election Day.

Yet several conservatives have suggested that the Republican Party should do everything in its power to keep Biden as the Democratic candidate, expressing worries that a younger replacement could defeat former President Trump, 78, in November.

Newsweek has reached out to Smith for additional comment.

Last week, right-wing commentator Tim Pool tweeted, "We must support Biden at all costs and not let Democrats replace him."

The popular X account @KaladinFree also wrote after the debate, "The mood among MAGA is shifting from jubilation to fear that the Democrats might just replace Biden with someone who can actually win. They are like the dog who chased the car and finally caught it."

Strategists previously told Newsweek that Trump should want Biden to stay in the race.

"Replacing Joe Biden would be unprecedented, but it would completely flip the script for the 2024 presidential election," GOP consultant Matt Klink told Newsweek last week. "Instead of a comparison between the two candidates both with significant negatives, it would create more of a 2020-like climate where Donald Trump becomes the issue."

Senator Lindsey Graham, a Trump loyalist, echoed those sentiments on Sunday, telling CBS News that if Biden is replaced, it would be come "a dramatically different race" for the Republican Party.

"If Biden steps down, [Vice President Kamala] Harris is going to have to pick somebody to help her," Graham said. "If she does become the nominee, this is a dramatically different race than it is right now today. I hope people are thinking about that on our side."

Republicans have ramped up attacks against Harris in recent days as speculation grows about who could take Biden's place. Harris has been one of the most obvious choices, given her access to campaign funding and role as VP. She's also nearly two decades younger than Trump, who would be the oldest president to ever be inaugurated if he wins in November.

Trump himself gave Harris a new nickname last week, calling her "Laffin' Kamala Harris," and suggesting that she could be his "potentially new Democrat Challenger."

"She did poorly in the Democrat Nominating process, starting out at Number Two, and ending up defeated and dropping out, even before getting to Iowa, but that doesn't mean she's not a 'highly talented' politician! Just ask her Mentor, the Great Willie Brown of San Francisco," Trump wrote on his social media platform, Truth Social.

Biden has insisted that he would not withdraw from the race, making several public statements quashing the idea and reiterating his position in an extended interview with ABC News last week.

"I don't think anybody's more qualified to be president or win this race than me," Biden told ABC News anchor George Stephanopoulos.