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 planned to accept 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.

Michigan is the second state after Utah to affirm that his name will be presented to voters. His campaign or an allied super PAC say they’ve collected enough signatures in several other states, including the battlegrounds of Arizona, Georgia, Nevada and North Carolina, but they haven’t yet been validated by elections officials.

Third-party and independent candidates face long odds in a U.S. political system largely built around two major parties. Kennedy has acknowledged the hurdles he faces and urged Americans to “take a risk” and vote for him, saying the biggest obstacle to his campaign is the belief that he can’t win.

Kennedy is a leading activist in the movement that rejects the scientific consensus that vaccines are safe and effective, and he’s built a fervent base of support among voters disenchanted with American institutions.

Stung by losses in two of the last six elections that many Democrats blame on third-party candidates, the Democratic National Committee has pledged a full court press to challenge Kennedy, including legal challenges to his ballot access and ads linking Kennedy to Trump supporters.

The anti-vaccine group Kennedy led for years, Children’s Health Defense, currently has a lawsuit pending against several news organizations, among them The Associated Press, accusing them of violating antitrust laws by taking action to identify misinformation, including about COVID-19 and COVID-19 vaccines.

(AP)