Remember when Republicans thought being obstructionist was a bad thing? Well, check out this comment by Sen. John "Boy that Box Turtle makes me hot" Cornyn in Roll Call (Sub. required)
“We have to give some flexibility to those in cycle in those states of
particular challenge,” Cornyn said. Referencing the GOP’s ability to block
Senate action, he added: “It’s nice to have all 49, but all we need is 41."
So, when the GOP was in control, filibustering was bad. So bad, they sought to outlaw it as a practice. But now that the GOP is in control, it's a legitimate practice of a minority party.
I'd question their intellectual honesty, but that's a bit like questioning Britney Spear's parenting skills.