Progressives want the Supreme Court to decide cases based on modern notions of fairness and social justice, rather than on the law as written. Because progressives view the Court as a super-legislature, rather than as a neutral arbiter of law, they seek nominees to the Court whom they believe are willing to legislate certain outcomes from the bench.
The president should nominate and the Senate should confirm only those candidates who possess a sound judicial philosophy.
Here’s the issue of judicial philosophy in 60 seconds: