Washington — Robert F. Kennedy Jr.'s team is still aiming to be eligible for 270 electoral votes, the number needed to clinch the presidency, with voters set to begin casting their ballots as early as next month. 

Kennedy's campaign has been working to get him on the ballot in all 50 states and the District of Columbia, but he has some hurdles to overcome.  

Kennedy is on the ballot as an independent in a growing number of states — Alaska, Delaware, Colorado, Indiana, Iowa, Michigan, Minnesota, Nebraska, New Mexico, North Carolina, Oklahoma, South Carolina, Tennessee, Texas, Utah, Vermont, Washington and West Virginia. He's also on the ballot in California as the nominee of the American Independent Party, and in Hawaii, on his We the People ticket. Combined, those states add up to just over 200 electoral votes. 

But New York is denying Kennedy access to the ballot, based on his residency claim. And he's facing challenges in Pennsylvania, Nevada, Delaware and Georgia, as well as an objection to his candidacy in Illinois.

Getting on the ballot in enough states to secure 270 votes — just over half the 538 votes in the Electoral College — is no small feat for a third-party contender. The Kennedy campaign is still pushing, since many states have deadlines this month. 

The Kennedy campaign in April said it's trying to evade legal battles by picking the right time to hand in the petitions, holding onto the signatures until the 11th hour in hopes that the signatures will face fewer challenges.

In addition to varying state regulations for ballot access and expensive legal battles, Kennedy faces opposition from Democratic groups aiming to undermine third-party campaigns.

Earlier this year, the Democratic National Committee formed a team to challenge third-party and independent presidential candidates. The effort will depend on other groups like Third Way, MoveOn, and a new super PAC, Clear Choice, backed by allies of President Biden.

The stakes are high and we know this is going to be a close election," said DNC spokesperson Matt Corridoni. "That's why a vote for any third-party candidate is a vote for Donald Trump."

The Kennedy campaign in April said it planned to secure ballot access in all 50 states, dismissing suggestions that Kennedy aims to help former President Donald Trump's bid for the presidency by taking votes from Mr. Biden.

"Our campaign is a spoiler. I agree with that. It's a spoiler for President Biden and for President Trump," Kennedy said when he revealed his running mate, Nicole Shanahan, in March.

In some states, the time frame for collecting signatures is brief. Others have provisions for signature thresholds to be reached in every county of a state. More than half the states require independent candidates to have a running mate.

Collecting enough signatures isn't difficult in every state. Many only require 1,000 to 5,000 signatures. Louisiana requires no signatures and a $500 fee. Other states have higher thresholds. Texas requires over 113,000 signatures, and Florida requires more than 145,000. 

And those are the number of valid signatures required. Any third-party candidate needs to overshoot that target in order to make sure they have enough in case some of the signatures are found to be invalid. 

The Kennedy campaign says it's aiming to collect 60% over the signature threshold in each state. 

"We have the field teams, volunteers, legal teams, paid circulators, supporters, and strategists ready to get the job done," said campaign press secretary Stefanie Spear. "We are exceeding all our benchmarks and will be announcing new states each week."

But Bernard Tamas, associate professor at Valdosta State University who studies third parties, said Kennedy should be aiming higher — closer to double the required number of signatures. 

"I'm surprised they're saying it's as low as 60, you just can't take any chances," Tamas told CBS News in April. 

Collecting signatures is expensive. Kennedy's super PAC estimates that it will cost around $40 to $50 million just to collect all the necessary signatures, although Tamas noted RFK Jr.'s running mate, Shanahan, the billionaire ex-wife of Google co-founder Sergey Brin, has the financial resources. 

Collecting the signatures isn't the hardest part — it's the battle over the signatures that's the real fight, Tamas said. The Democratic Party will be fighting hard to invalidate Kennedy's signatures.

"You really have to prepare for a battle, so a lot of the cost is not actually getting the signatures, but actually the legal fees of fighting each state," Tamas said. 

Historically, there have been independent candidates who secured ballot access across nearly all states. In 1968, George Wallace, the former governor of Alabama, and in 1992, businessman Ross Perot both appeared on the ballot in all 50 states. Ralph Nader's candidacy in 2000 extended to 43 states. 

Only Wallace managed to win any electoral votes. Perot's impressive 19% of the popular vote in 1992 did not translate to any success in the Electoral College.

Perot's former campaign manager, Russell Verney, said third-party candidates must overcome more obstacles today than in the past.

"Every time there's a reasonably successful independent candidate, the state legislatures, which are made up of Republicans and Democrats, who by definition do not like competition, increase the state barriers to getting on the ballot," Verney said in April. "The requirements to get on these state ballots continues to get more onerous in every election cycle."

A successful third-party candidate has to focus on individuals who aren't being represented by the major parties, and that's a problem for Kennedy.

"He's all over the place, and it's really not clear what's the disaffected group he's trying to tap into," said Tamas. "He's running on conspiracy theories is part of it. But if someone's a conspiracy theorist, chances are they're going to support Donald Trump."

Kennedy's support is likely to drop off before November, Tamas predicted in April. 

But it's not yet clear whether Mr. Biden or Trump stands to lose more from Kennedy's presidential bid. 

"Nobody really knows for sure who he's going to take votes from," Tamas said. 

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