BTW, I did a little research re: Fortas and "the earlier filibuster." The fact pattern is:
Fortas is nominated (by LBJ) and confirmed by the Senate. Couple years later, LBJ nominates Fortas for CJ (Chief Justice). GOP and Southern Democrats filibuster, LBJ withdraws the nomination. The basis for the filibuster was NOT Fortas' ideology, rather his honesty and integrity were called into question. FOrtas resigned from the SCOTUS a year later, in the wake of disclosures relating to accepting money, etc.
So, if you're ever confronted with a comment that the Senate used filibuster against a judge, you have the facts.
The Estrada case is different. Bush did not capitulate, and in the wake of that, the Senate failed to deliver its "up or down" advice and consent (or not), after months. Unprecedented, AFAIK.
Of course the ultimate solution to what has become an imperial senate is the repeal of the 17th Amendment.