The last few days I've been logging in only first thing in the morning (I'm on holiday, and the family get annoyed if I'm on the Physics SE all day :-) and there have been more than 20 questions with close votes in the review queue. So all my 20 close votes get used up before I've even finished the review queue.
We can argue about the close policy, but that's a separate issue. Given our current policy on closing I have too few close votes to effectively implement the site policy. I don't know if the number of close votes is SE wide, or whether it's tweakable on a site by site basis, but given the Physics SE (probably) closes more questions than any other SE it would be nice if we could have more votes.
Before the flaming starts, please note that I am not commenting on whether our policies on closing questions are right or wrong. I'm just saying that 20 close votes per >3k user is insufficient to implement those policies.