If you want a very good idea of how difficult it is to create a third party, I highly recommend the linked three-part series on the Reform Party. It's a great look at all the shit one must put up with to create a political movement, and just how easy it can all fall apart.

They built local, county-level organizations that came together to form individual state parties that were allied with each other to take control of local governments and elect members to the US House. What modern third party has done that? None.

But the GOP began as a small, local movement of separate local and state Republican Parties, not a national one. It also grew out of a collection of former Whigs, disaffected Northern Democrats, and Free-Soilers. When the disparate state parties came together as one, they focused on their states.

Some may point to the Progressive (Bull Moose), Populist, Free Soil, or the Reform Parties. But those weren't parties so much as insurgencies, and they all either rejoined the two-party fold or were largely absorbed into them. Still others may point towards the creation of the GOP.

Most people aren't like that. They may seem that way, but they aren't. Abortion, the environment, the economy, etc., may be the most important issues to some people, but not the only issues. People gravitate towards the parties that address a broad range of issues. That ain't the third parties.

Modern American third parties, however, tend to be focused on specific issues, whether it be Libertarians with their extreme free-market ideals, Greens with the environment, and the Constitution Party's Biblical view of government, culture, and society. They are, give or take, single-minded.

Hell, the Constitution Party is a clusterfuck of ridiculousness. Which gets me to another point about the DEMs and GOP: they are coalition parties. Both are a collection of particular factions with their own ideas and goals that fit within a broader definition of liberal or conservative.

It should also be noted that organizing a massive national party infrastructure is like herding cats. Ask yourself why there isn't one Libertarian Party, but several, many of which spun off from the main party and consider themselves the true Libertarians. Same with the Greens.

That's what Kevin means by "building a new infrastructure from scratch." You have to build a party at the local level in order to fulfill state requirements. In essence, you're looking at community organizing. That's not easy, nor is it immediate.

But in others it's temporary, requiring a party to apply every year or election cycle. And even then, there are signature requirements, registration requirements, monetary requirements, and candidate requirements. If the threshold isn't met or you're not organized enough, you're shit out of luck.

Parties do no technically exist nationally. They are not recognized on the national level, but at the state level. And the several states have different rules to establish recognition, if they will recognize another party at all. In some states it's easy and (fairly) permanent.