He's already drawing a hefty 16% in three-way contest with Biden and Trump, according to a recent NPR/PBS/Marist poll. However, all the public support in the world will mean nothing unless RFK Jr can overcome a major hurdle for any independent candidate: getting his name on the ballot in 50 states and the District of Columbia. 

There's more to that feat than gathering signatures. "It takes significant expertise to navigate specific rules for every state and the requirements needed before signatures can even begin to be collected — and then to beat back the legal challenges that will almost certainly follow," writes Politico's Brittany Gibson. 

Time is a big factor, and one that makes the ballot challenge all the more daunting for Kennedy's campaign, given his relatively late start.