Undecided

What is an undecided voter? CNN reported on a town hall type meeting the President had with Stephanopoulos as the moderator. In this town hall an "undecided" read a question, word for word, and the way he read it was as if he had never heard the question before, the guy appeared to be very decided. My question is if it even possible for a person be undecided in this election? If the candidates were McCain and Biden I think one could be undecided because there would not be much difference between the two, but Trump and Biden are polar opposites. One saying they are undecided about those two is like one saying they are undecided on whether to be a Christian or a Satanist. What are they undecided about? This is my theory. If you are a conservative, conservative leaning, or vote mostly for Republicans, you are a Trump supporter, there is nothing to decide, you are all in and the idea of you voting for Biden is not even in the realm of possibility, because, even if you don't like trump personally, you know he is much better for our country and voting for Biden would be voting for socialism. If you are a liberal, left leaning, and vote mostly for Democrats, and undecided, it is because you are deciding between not voting at all, switching parties and voting for Trump, or worst of all just voting Democrat for what you know is the worst ticket in history. I do believe there are more people deciding whether they are going to vote at all than those who are trying to decide which candidate they are wanting to vote for. At this point, undecided voters are Biden's to lose.