It's not brainwashing when the voting system is specifically set up to give an advantage to the dominant parties and to suppress every minority party. There are valid reasons to be skeptical that a 3rd party could ever win without a reformed voting system.

Simple Math = brainwashing

FPTP makes 3rd parties counterproductive.

It's not fear. Third parties simply do not work with our system. If you want third parties to succeed, then we need to

• Get rid of the electoral college
• Ranked Choice Voting everywhere

It's not that simple. Several factors come into play.

The biggest systemic issues are the first past the post voting system and the electoral college (for president).

People who have even a simplistic understanding of how the system works and the track record for third parties know the odds are low. Those who are pragmatic will vote for Dem or Rep. In the current polarized political climate people are less likely to take a chance with a third party vote.

Also, the press mostly ignores candidates of other parties. So they aren't as well known and thus can't get popular enough to get traction.

If you really want more parties to have a chance, push for alternate voting systems like ranked choice, cumulative, etc.

This chart from fairvote.org compares a number of different systems based on their research.

In 2016 I voted for Gary Johnson because I thought there was really no way anyone would vote for the other two.

Things I wrote in a GE sociology paper