Sometimes, not voting for the major candidate, or writing in someone you know has no chance, is the best choice.

You can write in someone who more closely reflects your views. Even if that person has no chance of winning.

Voting for Nader as we did in the last presidential election was effectively the same as not voting.

No it was not. If nothing else, it reduced the percentage of the total vote that went to either Bush or Gore.

In my previous example, 100 million people vote. For 100 million different people.

The winning candidate receives 2 or 3 votes.

Yep, he's still President. But the situation is very different than if he had received 66% of the votes cast.

I suspect that if you believed that it was important for your vote to always have a positive impact on who won, you would always vote for one of the top two major candidates. But you didn't, so you don't. Right?

But having a "positive impact" does not always mean voting for the person who won. Again, in my previous example. The "positive impact" would be the realization that the winning candidate would be replace by someone who could muster FOUR votes.

As for Gore or Nader, it isn't whether they'd have not voted if Nader hadn't won.

They got up and the voted.

The issue for the Democrats is "how do we get these people to vote for our candidate in the next election".

Getting someone who's already going to vote to vote for you
-is much easier-
Than getting someone who wasn't even going to vote to get up and go vote and to vote for you.