More can be found here -- note the panel discussion's moderator is Slate's own Dahlia Lithwick.
Liu has written a lot about legislative policy, which also is beyond the job of a judge in various ways. Thus, e.g., he thinks welfare rights or education policy are necessary for national citizenship and the Fourteenth Amendment has a role to play. A left leaning approach, but even he (apropos Obama) sees this as mainly a legislative effort. The judiciary would interpret statutes, which they would generally hold were constitutional. There would be some role around the edges mainly procedural due process. The core actors would be legislative all the same.
It should be remembered that a lower court judge (even a justice, really) has a limited discretion to put into practice their particular understanding of the law, being bound by precedents and the individual cases they decide. This is all underlined by the number of unanimous or nearly unanimous rulings, though there can be some flexibility in the writing or breadth. But, there is enough wiggle room and debate for the individual judge and his/her judicial philosophy to matter.
I'd add, though Liu was sure to take the conventional line that it is not the case, that personal opinion influences this somewhat. After all, even he cited "human" judging here. Finally, though there was some attempts at "gotchas" and targeting of his strong criticism of Alito (long analysis ignored to focus on some strong adjectives -- fine, take it, Liu has the chops to survive it) and Roberts, the Q&A seemed (I skimmed some of it) pretty substantive. Well, fwiw, better than the Sotomayor hearings.
One would hope this sort of thing will continue when the justice nomination is up.