I think it's far more likely that if the Republicans fall apart, a large component will pivot and eat up one or more of those other parties to retain a Republican designation with slightly different values. It's a mistake to think of either of the two major parties as static.
This is in strong contrast to Westminster parliaments, where political parties are for the most part a monolith, only occasionally allowed a "conscience vote" (that's not to say there isn't infighting). To vote against the party is a very good way to get booted from the party, which as far as I'm aware is practically impossible in Congress, the closest you have is being expelled from a caucus.
But they do not have those votes--largely because many people who share your general opinion keep hammering home the message that if you do not vote for one of the top two candidates, then at best your vote does not matter, and at worst it destroys America.
My concerns are that Trump is a misogynistic sleaze who will undermine US diplomatic prestige, be generally ineffective as a government executive trying to act like a business executive, and will damage international trade; and that Clinton is a corrupt politician who will undermine US liberty, continue indefinitely the harmful policies of Bush II and Obama, and will damage the rule of law. The fact that those third-party candidates have a statistically zero chance of winning actually makes me more comfortable in voting for one of them.
On the off chance that the Republican party could finally destroy itself by choosing an even more unsuitable candidate next time around, I want the Libertarian Party to be strong enough to take its place. And on the even more remote chance that the Democrats self-destruct, I want the Greens to be big enough to step into their shoes. Having lived in Chicago, I have had enough of oily, corrupt Democrats in power. And having lived in the South, I have also had enough of smarmy, bigoted, hypocritical Republicans in power.
They are never going to die out if people keep voting for them and sending them money!
> On the off chance that the Republican party could finally destroy itself by choosing an even more unsuitable candidate next time around, I want the Libertarian Party to be strong enough to take its place.
Don't kid yourself about some other party ever taking the place of the Democrats or Republicans. The best you can hope for is that the libertarians gain more influence than they currently have through the larger Republican party consuming them. Whether you view this as a needed shift in the right direction for the Republicans or not enough of a shift and at the cost of any power the libertarians had likely depends on how far you lean libertarian. Same with the Democrats and Green Party.
Our two party system hasn't survived for as long as it has because each party innately catered to it's constituents needs from the beginning. Each party has shifted greatly over time to track what their constituents cared about.
> Having lived in Chicago, I have had enough of oily, corrupt Democrats in power. And having lived in the South, I have also had enough of smarmy, bigoted, hypocritical Republicans in power. ... They are never going to die out if people keep voting for them and sending them money!
They are never going to die, period. But that's okay. They don't need to die, they just need to change, and there's plenty of precedent for that.
In presidential elections, because of the US political system, you really do have just two choices. You may lament this - I have! But it's the world we live in. Saying you'll vote for a third party candidate to "register your complaint" is a null gesture.
If you really care about politics, you'd have to work to push the party of your choice in the direction you want. This is long, hard work, and happens outside the presidential cycle. You have to march with signs, attend boring meetings, and persuade people you just met.
Complaining about the broken system every four years is neither mature nor effective.
I am moved to write this because, for multiple election cycles, I was that guy, until I realized my folly.
Your choices are Clinton + Kaine (Dem), Trump + Pence (Rep), Johnson + Weld (Lib), and maybe Stein + Baraka (Grn). No one else could win without deadlocking the electoral college.
To oppose Clinton is little more than calling a turd sandwich a turd sandwich. One does not also need to point out that her douche opponent is a douche.
While the US elections systems virtually guarantee a two-party system, it does not mean the two on top always have to be the same parties. If the Republicans fall apart after this, Libertarian, Green, and Constitution will certainly devour the corpse, and one of them will eventually grow fat enough to take its place and push the others back down and away from the table.
I do wish a pox on both houses--along with a hemorrhagic fever, parasitic worm infection, and some kind of blotchy skin rash. I am not staying out of the election. I think Clinton would competently lead the country in the wrong direction, and I think Trump would be a national embarrassment on multiple fronts. Strategically, the best strategy I could follow would be to bash the presumptive front-runner, whomever it may be, to keep the two major candidates as close as possible, and hope that the minor candidates can somehow win enough states to deadlock the electoral college.
Note that it is unlikely that is the primary motivation for Wikileaks. But it does show that this game is not a zero-sum either-or.