I voted to close the question because I believe the question covers the same ground. My vote is one of five needed to close: people can disagree with me, and that's fine.
Obviously, you disagree that your question isn'tis a duplicate of an earlier question; that's fine too. It would be helpful and constructive to myself and others if you explained why it wasn't a duplicate, but that's your prerogative to do so.
The question then becomes when two people disagree, who gets to decide which questions are locked and prevented from being closed by 5 independent people? Obviously, you have a conflict of interest in preserving your own questions, so it shouldn't be you. As I voted to close the question, you probably wouldn't be satisfied with me being that arbiter.
Let's say there is someone independent arbitrating the question. If someone else decided that your question shouldn't be locked, what then? Would you create a new topic declaring that there should be a new level to prevent people from not locking your question from close votes?
The system works: people are going to disagree, that's why we vote.