Everyone wants to start at the federal level, which is crazy, because federal politics is entirely party dependent. If you're an independent at the federal level, you're still caucusing with either the Democrats or the Republicans, or you have no power.
The correct place to start a third party is at the city level, then the state. States control voting laws and who gets on the ballot. If any third party were serious, they'd be spending every penny they had trying to get into state legislatures, where they might actually do some good. You'd be surprised, though, at how few third parties have any idea what the real barriers to their success are. I've worked with a half-dozen third parties, and none of them from the Socialist, to the Greens, to the Libertarians understand how the party system controls electoral politics or what they might be able to do about it.
The best of them are probably the Libertarians, who waste a shitpot of money on big name federal candidates, but at least have slowly come to recognize that party building happens locally. Unfortunately, the position they mostly can win are dogcatcher-level positions. The number of independent state legislators is still woefully small. And yet, it's state law that determines who gets on the ballot, and what hurdles have to be cleared, not to mention whether electors are handled proportionately or not (which is the big issue they should all be fighting for if they hope to have a chance at a federal position.)
Most of the independent state legislators were elected as either Democrats or Republicans and then later changed their affiliation. Vermont is probably the best in regards to independents, and they have a total of seven in the House and two in the Senate, out of one hundred and fifty in the House and thirty in the Senate. New York has a handful of "independent Democrats" which is about as meaningless as treating Lieberman as a real independent.
