For weeks, Trump and his allies have been railing against vote-by-mail, which Democrats have sought to expand amid the coronavirus pandemic, claiming it allows for manipulation and fraud.
Most Republicans have embraced the president's rhetoric, but some party members believe that the attempts to vilify postal voting could depress GOP turnout.
"The fact that you have so-called party leaders parroting Trump's BS on vote-by-mail is basically putting a knife to their own electoral throats," former Republican National Committee Chairman Michael Steele said.
Conservative elections lawyer Chris Ashby said that there are "legitimate" concerns about the controversial practice of ballot harvesting, which is legal only in California, and the post office's ability to handle the sheer volume of ballots.
However, Ashby pointed out that "the national tide has clearly turned in favor of expanding opportunities to vote."
"Experience in Florida, for example, shows that Republicans can win mail ballots. But that's not going to happen if the GOP spends all its time fighting vote-by-mail and casting doubt on it. In both the short and long terms, all those resources and efforts would be better spent trying to win mail-in votes."Indeed, in Florida — the nation's largest swing state — the Republican Party has traditionally beaten Democrats among absentee voters. Furthermore, many seniors, who are considered to be a key element of Trump's base, prefer voting by mail.
According to the R Street Institute, a conservative-leaning think tank, the GOP would, in fact, benefit from expanding absentee balloting.
For instance, in 2016, Trump won Montana, Utah and Arizona, where around 70 percent of voters cast their ballots via post. Similarly, Republican Sen. Cory Gardner won in Colorado after the state expanded mail-in program and Mike Garcia won a seat in the House of Representatives in the blue state of California.
The R Street Institute also noted that conservative governors in Alaska, Ohio, Nebraska, New Hampshire, Maryland and Missouri have called for an expansion of mail balloting.
Per The Hill, a recent Harvard CAPS-Harris poll established that 70 percent of American voters, including 71 percent of independents, support the program.
Trump's attacks culminated earlier this week when he floated delaying the November election.
Members of both parties rejected the president's proposal, with Senate Majority Leader Mitch McConnell noting that the U.S. has never postponed an election.
In an interview, Speaker of the House of Representatives Nancy Pelosi described Trump's allegations as an attempt to suppress turnout.