Independent presidential candidate Robert F. Kennedy Jr. has secured a place on the ballot in the battleground state of Michigan, state officials confirmed Thursday, elevating his potential to affect the November election.

Kennedy’s independent bid has spooked allies of both President Joe Biden and former President Donald Trump, the presumptive Democratic and Republican nominees, who fear his famous last name and dedicated support among a slice of disaffected voters will be enough to tip the election.

Biden scooped up endorsements from at least 15 members of the Kennedy political family during a campaign stop Thursday in Philadelphia.

A spokesperson for the Michigan secretary of state’s office said the Natural Law Party, a minor party with a line on the state’s ballot, nominated Kennedy at a convention.

Kennedy faces an expensive and time-consuming process to get on the ballot in all 50 states and the District of Columbia without the backing of a political party.