

The chance isn’t just slim. It’s astronomical.
The chance of Cornell West winning is probably smaller than a bit-flip happening, switching your vote to another candidate. That’s how little chance your vote would have to make the country a better place.
On the other hand, every vote not casted for the only viable non-Trump candidate helps Trump.
I’m European and would love for you to have the option to vote for proper social democrats or greens (especially greens!). But please, every US citizen needs to do their part to not get fascists get hold of your country.
It’s sad to say, but if you don’t vote for the democratic candidate, you might not have a chance to vote 3rd party in 4 years. (I don’t like fear mongering, but it’s a real enough possibility)
Clearly you don’t understand the first-past-the-post system the US presidential election utilises.