No, Bolton has one vote and the spotlight on him as he explains who he is voting for and why. If he wanted to make sure Trump lost then he would use his limited time in the spotlight to make the case for conservatives voting for Biden.
No. You are mistaken in the idea that there is only one way to make sure Trump loses. There are at least two. One is to work to increase the number of votes Biden gets. Another is to decrease the number of votes Trump gets.
If someone can convince voters not to vote for Trump and to vote for Biden, that's great. But in the case of many potential Trump voters, it may be simpler and more achievable to simply get them to decide not to vote for Trump.
For some strong conservatives, thinking they have to vote for Biden if they don't vote for Trump may be a bridge too far. And if they think there are only two choices -- vote Biden or vote Trump -- and the more they think about Biden, the more they can't stand the thought of voting for him -- then that potential non-vote for Trump may switch back to a vote for Trump come election day.
So it makes sense for those who genuinely like what Joe Biden stands for and who genuinely like what they think he'll do if he's elected to make the case for people to vote for Joe Biden. Those folks are in a good position to make a strong and believable case for why they think Biden would be a good president and is well worth voting for.
And it makes sense for those who genuinely detest what Trump is doing and genuinely think we can't afford to have him continue being president to make the case for people not to vote for Trump. Those folks are in a good position to make a strong and believable case for why re-electing Trump is a mistake we can't afford to make.
Bolton appears to fall into the second category. He's not speaking out against Trump because he thinks Biden is great, he's speaking out because he thinks Trump is a disaster. That puts him in a good position to reach other conservatives who also aren't particularly keen on Biden but who can possibly be persuaded that keeping Trump in the White House is worse than having Biden in it.
My impression, and I could be wrong as I don't watch a lot of news, is that Bolton didn't go out of his way to say he doesn't plan to vote for Biden; he was asked by a reporter whether he planned to vote for Biden and he answered the question. But if our aim is seeing Trump defeated, then the answer he gave, that he doesn't plan to vote for Biden, is probably a better one for achieving that end. The people Bolton may be able to reach are people who aren't fond of Biden but are having doubts about Trump -- doubts someone like Bolton, who feels the same way, can help magnify until they make the decision not to vote for Trump. But if Bolton appears to be saying he likes Biden stands for, he'll be moving away from rather than drawing closer to those people. He'll be making himself someone they'll be less likely to listen to and someone who will be less able to convince them.
Segnosaur said that if someone says they don't plan to vote for Biden then they're lying if they say they don't want Trump re-elected. I'm saying that's wrong. It's quite possible to honestly not want to see Trump re-elected but to be unwilling to vote for Joe Biden.
If enough people can be convinced not to vote for Trump, then Joe Biden will win. And John Bolton appears to be working hard to convince people not to vote for Trump. If you really want to see Trump defeated, then calling people like Bolton -- people who plan not to vote for Trump and who are encouraging others not to vote for Trump -- insulting terms like liars and idiots is not a very good approach.