It really depends on the election and the circumstances of the race. Third-party candidates often capitalize on dissatisfaction with the two major party candidates or the failure of either to address the concerns of a particular demographic. They may gain resonance if they can articulate a platform that is distinct from either major party, covers a wide array of pressing issues, and resonates with a broad cross-section of voters. Beyond that, they need to be able to raise enough money to get their message out and build an organization that can turn out a base of supporters. With individuals like Andrew Yang, Howard Schultz, and Marianne Williamson making waves with their White House bids, there may be a very large field of third-party candidates vying for attention.