Some Republicans are threatening legal challenges to keep Biden on the ballot. But will they work?

Washington — Allies of former President Donald Trump have floated the possibility of legal challenges to try to keep President Biden at the top of the Democratic ticket, even though he has ended his campaign, but election law experts believe it's unlikely such court fights aimed at blocking Vice President Kamala Harris' presidential candidacy will gain traction in the federal courts.

In an interview with ABC News' "This Week" hours before Mr. Biden dropped out of the presidential race, House Speaker Mike Johnson suggested Republicans could bring lawsuits in states where he is not on the ballot.

"Every state has its own system and in some of these, it's not possible to simply just switch out a candidate who has been chosen through the democratic — small D — democratic process over such a long period of time," he said Sunday. "So, it would be wrong and I think unlawful in accordance to some of these state rules for a handful of people to go in the backroom and switch it out because they don't like the candidate any longer. That's not how this is supposed to work."