I have copied "Follow the chain to the origin" from @seth answer
Today I have seen a post and it is a dup.
I have closed it against a post 1 which is also a duplicate of another post 2
Here, If you observe, the post 1 answer has 100 upvotes, even it is dup.
It means that one is the better question as more people find it . If I follow chain, I have to close against post 2, then OP will miss post 1. (Here need to observe, the gap between post 1 & 2 is very few months).