So many things to be said. But this is maybe the most important point.
Every nominee put forward by Trump, or any future Republican president, will receive exactly the same treatment because the opposition understands that they cannot, have not, and will not achieve their societal and institutional goals at the ballot box. They know that they must change society by fiat. And that has largely been done, and they hope, will be done, by activists SCOTUS justices.
Judge Kavanaugh could have been any other nominee and the tactics would have been identical. Leftists know that the American people are not in agreement with their radical un-American goals. So they must be ruled by their elite betters.