Is "chicken and egg" the right metaphor to use? I generally agree with what you said, but it always comes down to how to get the numbers for the votes. Both sides are always afraid of "throwing away their vote" on a third (or fourth or fifth) party candidate. How do you break that barrier?
Convince both sides that they are throwing away their vote by voting for whatever trash the main parties regurgitate to be picked from, and convince people that it's not the end of the nation if "their" party looses an election or three if the resultant shift to a third party allows for 1. a replacement of one of the big two, or 2. one of the big 2 instituting massive reforms to bring them closer to what the country is supposed to be.
So far I've been spectacularly unsuccessful at convincing folks of that. They'd rather vote for trash out of fear of "losing" and further cement the uniparty's control. The outliers are folks like Boomhauer who seem to say they are voting for the candidate (Trump) that will cause the most ruckas and damage to the establishment, which I actually understand and sympathize with.
Not sure what you mean by decades. The US has been a 2-party system since the beginning.
I feel like the "This is the End!!! You have to vote for [party schmuck] or the country ends THIS YEAR!!!!11!!" method of campaigning is more prominent in the later half of the 20th century and today then it was at the beginning of the country, but I may be mistaken. Certainly even at the start the Founders had disagreements about the direction of government. While we are (and have been) a two party system, pressure from the voters has managed to not only switch which parties are the "two" (Whig, Democratic-Republican, Federalist, Bull Moose for one shining cycle) but also shift the direction of a major party (Democrats circa early mid 20th century, and maybe again circa 2016? we'll see). But none of that pressure can be brought to the parties if the faithful are unwilling to leave or abstain no matter what senile fool is offered to them.
Do you think there's a way of changing the built-in tendency toward a 2-party system before this November's elections? What should we do differently? I'm open to changing it, but won't it take at least a few election cycles?
Nope. I've lost hope of even convincing people not to vote for Biden. The Fear Porn is too strong and consistant
I think the big question you're not asking is why Republicans are so insistent on nominating Trump instead of the Person Who Obviously Should Be the Republican Nominee (PWOSBRN). We had a much better choice within the 2-party system, but we went with Trump, instead. Why? That's not because of any party system, or winner-take-all, first-past-the-post elections. It's because we wanted to put our feels (gotta own the libs! love Trump!) over electing the PWOSBRN. PWOSBRN has a record of combining massive electoral success, even in blue areas, while simultaneously advancing an America-first, pro-liberty, anti-SJW platform. The 2-party system didn't deprive us of that. That was a self-own.
You'd have to ask a Republican. I don't understand either of the apparent nominees. Unless the "F it burn it all down" contingent is bigger than it seems in both parties, which I guess is possible.