Your humble servant has borne witness to what appears to be a serious divide on the Democratic side of the electorate. Many Sanders voters are holding forth that they will not be casting a vote for Joe Biden in the general election, promising either to cast a third-party vote or to sit out the election. Whether that amounts to an effective vote for President Trump depends on where these erstwhile Sanders voters reside.
California will most certainly go for Biden in the general election. Mississippi will doubtlessly cast its electoral votes for Trump. Those individuals sitting out the election, either effectively or actually, probably won’t affect the outcome. In Arizona, on the other hand, where the race is close, Sanders voters sitting out the election could be outcome determinative.  And so it is in some other states.
Now for those who sincerely don’t see any meaningful difference between the major party standard-bearers, what I am about to say won’t have any impact. But for those who really, if secretly, harbor more loathing for one of the candidates, I must urge that they once again block their sensory pathways and vote for the candidate they loathe less. Yes, I am counseling that they vote for the lesser evil, as disdainful as that seems to be.
Third parties, like the Greens and Libertarians, are ideologically based. They come together because its members view issues in the same or similar manner. The Democratic and Republican parties, on the other hand, are coalitions of interest groups. These interest groups band together in order to increase their political strength. Because of that, the Democrats and Republicans will remain the major parties. Here is the explanation using a thought experiment:
Suppose you have twenty different interest groups, each of them forming their own political party. Then suppose two of them recognize that they have interests that don’t conflict with one another, so they decide to team up and run a single candidate. With plurality voting such as we have in these United States, the two parties who unified into one will win the election.
In the next election, the other parties, being rational actors, will seek their own alliances. It is easy to see how this process will eventually result in two large parties. It won’t result in one big party, because the less numerous or powerful interest groups will freeze out the groups with fewer people or less power, forcing them to split off into another party.
What if a couple of the original parties decide that such coalitions are an affront to their ideological purity? These are doomed to a political wilderness where they will never enjoy electoral success. Their members may feel good about themselves, but they will never persuade enough people to discard their self-interest for philosophy. In a democracy, people vote their interests by and large, even if they dress up their interests in terms of good and evil. To not vote your interest you have to be deceived as to what your interests are. Or you have to be rich enough that it won’t matter. (Of course, there are a lot of rich people who vote in the interest of staying rich.)
I don’t want to be misunderstood here. I’m not saying that our situation is a good thing. I’m with George Washington on this. I think political parties are a public nuisance, and I’m all for getting rid of them. But we haven’t gotten rid of them yet, and we have to play in the ballpark we’re in.
So, if you want the candidate you vote for to win, you have to vote for the Democrat or the Republican. You may have noticed that, with the exception of a rare local election here or there, that’s the way it always works out. If you vote for a third-party candidate, understand that you’re casting a protest vote, and are effectively sitting out the election; and I submit that there is no evidence that sitting out elections accomplishes anything useful.
Yes, this is a very disagreeable situation. It ought to change. But the way to do that is to work to change the system, not refuse to participate. Sometimes we have bad choices. But we have to choose all the same.