With hindsight, given the dirty tricks the GOP played in order to secure Trump two Supreme Court appointments; the Dem’s should have just gone full radical and take the Senates refusal to put the nomination up for a vote as a tacit ‘approval’ (seeing as they didn’t technically vote him down), and sit Garland on the court.
It’s the political equivalent of not negotiating with Terrorists, akin to the Paradox of Tolerance.