Robert F. Kennedy Jr. dropped out of the presidential race and endorsed former President Donald Trump, but his plan to boost the Republican candidate by taking his name off the ballot in 10 battleground states is being thwarted by states that say it's too late to do so.

"Our polling consistently showed that by staying on the ballot in the battleground states, I would likely hand the election over to the Democrats, with whom I disagree on the most existential issues," Kennedy said at a news conference before endorsing Trump. But three of those states  — Michigan, Wisconsin and the less competitive Colorado — have already denied his request to remove himself from the ballot, citing election laws.

"Minor party candidates cannot withdraw, so his name will remain on the ballot in the November election," Cheri Hardmon, a spokesperson for Michigan's secretary of state, said in a statement to The Detroit News. "The Natural Law Party held their convention to select electors for Robert Kennedy Jr. They cannot meet at this point to select new electors since it's past the primary," she continued, referring to RFK Jr.'s successful bid to get the small party to nominate him.

The Wisconsin Elections Commission voted 5-1 to block his removal on Wednesday, citing state law that says "any person who files nomination papers and qualifies to appear on the ballot may not decline nomination."

Kennedy, who is reportedly trying to help Trump in order to receive an important post in his second administration, did successfully remove himself in other battleground states such as Pennsylvania, Arizona and Nevada. The situation in North Carolina is unresolved, though election officials told state outlets that Kennedy's name has already been printed on some ballots.