at least since 2001 democrats have been identifying potential conservative supreme court picks:

Republican Judiciary Committee staffers improperly gained access to the Democrats’ server and downloaded Dems’ emails and documents. In one purloined email, an aide to Dick Durbin told his boss that liberal activists in the meeting “identified Miguel Estrada (D.C. Circuit) as especially dangerous, because he has a minimal paper trail, he is Latino, and the White House seems to be grooming him for a Supreme Court appointment.”

strategies besides accuse assult:

-nominee not providing enough information.

-they demanded he hand over the confidential memos

-label as controversial - due to inability to get 60 Senate votes.

-attack race - white is racist or minority is not latino enough etc

https://www.washingtonexaminer.com/because-he-is-latino-the-glorious-history-of-the-democrats-filibuster-fight

https://www.nationalreview.com/2003/05/masters-obstruction-mario-h-lopez/