With Mr. Trump trailing Joseph R. Biden Jr. in most national and swing-state polls, Republicans are again trying to help third parties that may appeal to Democratic voters and siphon off votes from Mr. Biden. This is taking place alongside a broader pattern of disinformation and skepticism by the president and his allies that has sown confusion and undermined confidence in the election.
Supporters of the president have also been trying to advance the candidacy of Kanye West, the billionaire hip-hop artist, confident that he can cut into Mr. Biden’s vote total. Democrats have portrayed the effort as a “dirty trick” and exploitative of Mr. West, who has bipolar disorder.
Republican efforts to aid the Green Party are not new. In 2016, a billionaire backer of President Trump, Bernie Marcus, the co-founder of Home Depot, provided support to Jill Stein, the Green candidate, according to people with knowledge of the strategy, who said the effort was done with the knowledge of some officials at the Trump campaign and its chairman at the time, Paul Manafort. (Mr. Manafort was subsequently convicted of eight counts in an unrelated financial fraud trial.)
It was not clear if Mr. Marcus’s support, which has not been previously reported, included bolstering the party’s effort to get on the ballot or funding a social media campaign, or if it went toward some other purpose.