Will the 2 party duopoly ever end?

[Person Man]

Everything eventually ends, right?

[Person Man]

The biggest factor would be if the existing parties at some point fail to absorb a political movement in substantial form that thus requires it to go outside of the existing tents, but that typically just reshuffles the deck chairs and you end up with a new party system with one of the old ones splitting between the new party and the older former competition (basically what happened in the 1850s).

What stops that from happening now is that national parties' apparati have become very good at finding new sources of discontent, buying them out, and astroturfing the whole thing.
Republicans have been very good at assimilating new movements but Democrats still think new movements need them more than the Democrats need the new movements.

That's where the next big potential reckoning of the system could be. The economy has been to this point unfair but there has been opportunity out of the sheer length stability and growing scale. Now that the economy is bad, there's opportunity for either the groups on the left to be the origin of a new successful party, for the Democrats to absorb them, or for the movements to abate

 If there's a V shaped economic recovery, I could see the far left mellowing out like they did in the 90s and the entire thing not happening. If the economy doesn't come back quickly and Democrats still perform poorly, that makes things more interesting.

[Person Man]

The biggest factor would be if the existing parties at some point fail to absorb a political movement in substantial form that thus requires it to go outside of the existing tents, but that typically just reshuffles the deck chairs and you end up with a new party system with one of the old ones splitting between the new party and the older former competition (basically what happened in the 1850s).

What stops that from happening now is that national parties' apparati have become very good at finding new sources of discontent, buying them out, and astroturfing the whole thing.
Republicans have been very good at assimilating new movements but Democrats still think new movements need them more than the Democrats need the new movements. 

This just isn't really true.  The Democratic coalition has changed just as substantially as the Republicans have over the contemporary era.  Just look at how much the Democrats have zoomed left on issues like the environment, immigration and censorship since the 1980s.

The U.S. will never have a major third party because the GOP and Democrats are big and diffuse enough to morph their coalitions into whatever they need to do in order to win.   

What does "left on censorship" mean? They were arguably the most pro-censorship in the late 1990s. And censorship isn't really a left-right thing, anyways. During the W administration, there was a substantial conservative cancel culture.

[Person Man]

I think the two party system eventually will end. Not sure when but I think it eventually could happen.

The Democrats won’t be facing the Republicans in the US presidential election of 13648, if that’s what you mean.
I could see a situation where one party keeps winning no matter what and eventually one joins with the moderate factions of the other one but the last two or three times that could of happened, the other side put up a moderate that didn’t give in to the others side’s demands entirely though they did acquiesce to what would eventually be considered too much.