While the Republicans curtail democracy for voters, the Democrats curtail it for candidates.
The statewide ballot in Vermont includes 5 candidates for President: Rocky Anderson of the Justice Party, Gary Johnson of the Libertarian Party, Peta Lindsay of the Party for Socialism and Liberation, Barack Obama of the Democratic Party, and Mitt Romney of the Republican Party. Notably missing are Stewart Alexander of the Socialist Party and Jill Stein of the Green Party.
It turns out that in 2009, Vermont changed its ballot access rules for third parties (but not for the Dem/Rep duopoly), requiring petitions and candidate selection 3 months earlier than the duopolist parties. Rocky Anderson's campaign successfully sued to have more time to gather signatures, but Vermont's Dem/Rep/Prog Secretary of State Jim Condos stated that although the court ruled against the new rules, the court decision only applied to the Justice Party. Condos said that each party would have to sue on its own behalf. And so the Green Party is not on the ballot. And although Liberty Union, the long-established Vermont affiliate of the Socialist Party, filed their nomination of Stewart Alexander in August along with the rest of their slate, Condos rejected their inclusion on the ballot for President. Again, he said they would have to sue to get on the ballot.
(And if all that weren't enough to keep you off the ballot, some (most? all?) states require filing as a write-in candidate to be counted as such.)
I might as well also mention here the fraudulent games of Vermont's Progressive Party, which often runs a candidate in the party primary only to prevent a candidate running against the Democrats. Most recently, party chair Martha Abbott put her name on the primary ballot because she did not want a Progressive candidate to run against Democrat Peter Shumlin. As promised, after she eked out a win against a write-in campaign, she withdrew, so there is no Progressive candidate for governor on the ballot despite the clear wish of many Progressive voters.
Some people might think it's nice that our choices are thus already made for us, but you can't call this democracy.
Also see: "Basic Steps of Election Reform"