They have a first past the post parliamentary system, derived from the UK. The US has a separation of powers between its executive branch and its legislative branch.

The way to build third parties is by reforming the democratic system state by state to have a ranked choice system open non-partisan primary to select the top two final candidates followed by a general election between these two candidates for each election to elect a representative or president.

It helps mitigate the flaws of the ranked choice system to have it stop at the final two and let the voters choose between these final two choices. It helps get candidates that are at the center of voter opinion distribution.

This means the hard work of mobilizing together and working across partisan lines, recruiting the majority of Americans that are pro-democracy in each and every state.

Shittiest take on this community by far.

It's an myriad of reasons from what I can tell. Americans are conditioned to think along the status quo lines even if there is certain degree of freedom of thought. The American corporate media carves the political landscape to intentionally but subtly influence folks to pick either only Democrats or Republicans.

Another reason is that, I suppose rugged invidualism won out in the American society for better mobilisation. As you rightly pointed out, there just isn't grassroots activism among American people (not counting civil and lgbt rights which are undoubtedly grassroots activism and successful ones at that). But this isn't what it used to be. Before and in the early 20th century, there have been other third political parties still gaining respectable number of votes, the last one being the Socialist Party led by Eugene Debbs. He won a respectable 1 million votes as a presidential candidate while campaigning from prison during World War I.

Not sure what happened why political grassroots activism that could counter either Democratic and Republican parties died out, but my guess is that the proliferation of mass media in the 20th century may have had a hand to convince people to stick with two parties, as well as heavy emphasis on individualistic values.

I tried making a similar argument on Facebook in 2016 when Trump won.

I didn't vote for either of the top two, but I did vote 3rd party. I voted on someone that i felt would be just as good a fit as the other two at that time. I wanted change, and tried to get so-called friends to change the way they thought about voting. Some of those people were the kind to say "my vote doesn't matter. They'll elect whomever they want in office."

I even went so far as to draw a very shitty comic that pointed out the other options on the ballot, and how we as a society could push for political change BY VOTING.

Sigh.... I was called a classless human being by an immigrant from the UK I went to college with. Her friends, and even one professor kept blowing up my DMs calling me trash for not supporting Clinton. That election really showed me the true colors of people. Since then i just tell people i am "unaffiliated" when they ask which party i support.

this instance is well known for takes like these when it comes to politics unfortunately. its better to not engage with any sort of political posts on here.

Love shit like this because you all lack the same fundamental goddamn knowledge.

It's up to the states who goes on the ballot. There are only three political parties in the United States with enough support to get on all 51 (50 States + DC) ballots. Those are the Democrats, the Republicans, and the Libertarians. The Libertarians are just as fascist as the Republicains, but they don't have the guise of Christianity to cover it up, so they get pretty few votes. Beyond those three, It is entirely dependent on the state who you get to vote for. I, for example, get four choices in my state. The big two, the libertarians, and the Legalize Marijuana Now parry. The latter is a small party who's soul goal is getting marijuana legalized. Wanna vote for the Green party? Tough shit. I suppose write ins are an option, but there's roughly 200,000,000 people who vote, so good luck convincing even half of them to write your name down without a party supporting you.

In other words, "Lesser of two evils" isn't a mindset. For a lot of us, it's literally the only choice.