"The Dupehammer" refers to the ability of tag gold badge owners to unilaterally close and reopen duplicates which were asked in tags of which they have a golden badge.
It is assumed that tag gold badge holders are well-versed and community-trusted for the specific tag they hold a gold badge of. As such, their vote-to-close power is proportionally reflected by means of this "privilege".
Reference:
When did I get close-vote superpowers?
Increase close vote weight for gold tag badge holders
(Tag description taken from MSE)
