When Senators are on leave, they don't count toward 2/3rds, so it is currently at 6 of 9, or passage level.
I'm not sure I agree, based on my reading of CheeseWhiz v. Senate of Atlasia.
Interesting, as we've consistently used the "two-thirds of those present" rule for things other than amendments (notably cloture), both when I was PPT and with Sam Spade. And, of course, you only need five votes for passage with a Senator absent as a simple majority is then of those present. It seems like a remarkably bad SC ruling, but whatever.