Maybe they learned the concept from the Democrats back when they were talking about what they would do if Bush got another chance to nominate a Justice as a lame duck president. Of course Schumer was only talking about the last 18 months of the Bush presidency not the last 10 months. Obama will have to pick carefully if he wants a nominee to have a shot at a hearing and even more carefully to keep them from getting Borked.
It's important to note, I think, the difference between, "I will urge my fellow senators to not confirm ideologues" and "not confirm except in extraordinary circumstances"
and
"We will not allow a vote on anyone"
These are not the same thing.
Schumer's comments are a Senator urging his fellows to vote no on ideologues. McConnell's comments are a Senator vowing to prevent votes.
If anyone thinks these are the same thing and represent a "they did it, too!" then they need to read again, while thinking this time.
Moreover, even if Schumer HAD said something as shameful as "we won't let anyone vote," recall that the Republicans and the White House both condemned it. To turn around and embrace the crimes of your enemy and repeat them make you either a petulant toddler or a sociopath. Neither reflects well on you.
But of course, Schumer didn't say that. McConnell dialed that right up higher.