"What Mr. Obama wants in a nominee isn't really "empathy" and "understanding." He wants a liberal, activist Supreme Court justice"

Karl Rove is suggesting that President Obama is not searching for a Supreme Court justice who is simply compassionate and understanding, but rather somebody who is a liberal activist. This indicates that Obama is trying to find somebody who will want to make decisions that remain in line with his own political beliefs and agenda. Rove is implying that Obama is searching for a justice who will be willing to make choices that are more progressive and liberal in nature, instead of somebody who will just be comprehending and empathetic. This recommends that Obama is searching for a justice who will be willing to make choices that are more in line with his own political beliefs and agenda.