The Democrats would have done the same to Brett Kavanaugh, but couldn't, because they didn't control enough Senate seats. They instead tried numerous other tactics that I would not call "principled" to stop the nomination, and failed.
Democrats basically pioneered the use of the filibuster to block judicial nominees during the Bush Jr era, which was a pretty clear instance of ethically questionable, "innovative", partisan obstruction.
They were forced to relent when republicans gained enough seats in Bush's second term and threatened the "nuclear option" (the elimination of the filibuster).
Republicans made every effort to outdo the democrats during the Obama years with filibusters. Harry Reid then went nuclear to push through Obama nominees with simple majorities (removing the best tool democrats would have had to oppose Kavanaugh today). The capstone for the republicans of the Obama era was blocking Merrick Garland.
Now we have Kavanaugh. There's just no great way to interpret the democrats moves as principled here, even if you think Ford's allegations are credible (I do). The democrats needed to to obstruct and delay until the midterms, and the only tools to do it were delays, scandals and public pressure on the senate swing votes.