Yes. The forced two-party system inevitably leads to an us-versus-them mentality. Everything gets divided into Good Things done by Us, and Bad Things done by Them. There's no room for nuance, everything has to be pushed to the extremes in order to get a handful of voters to flip.

In a healthy democracy with at least a handful of political parties the small groups of lunatics aren't going to poison the entire spectrum: they are mostly contained into the tiny extremist parties served by heavily biased extremist media. The vast majority of the population, however, is served by more moderate parties and more neutral media - where misinformation and blatant corruption is heavily frowned upon.

Turns out when people have a genuine alternative, they don't just stick with whatever shit they are trying to pull this time just because "the other guy is even worse".