Independent presidential candidate Robert F. Kennedy Jr. has a problem that goes far beyond the nearly insurmountable long odds that third-party candidates have to overcome in order to win a national election: He’s not raising money.

Perhaps the biggest indicator that a presidential candidate is garnering support or interest from voters is whether his campaign is generating large amounts of small-dollar donations. Without these, a candidate is forced to rely on high-dollar donors who quickly reach the legal maximum contribution threshold for a federal election.