Perhaps the most effective argument the White House can make in getting Sotomayor an easy confirmation among the Senate GOP is to make the case that she won't be dramatically different from the individual she will replace: Justice David Souter.
The argument risks, of course, the backlash of progressives. Souter was a Bush One appointee whose decisions grew more liberal over time but were hardly ideologically consistent. But the replacing-Souter-with-another-Souter charge could dampen conservative criticism. And, at this early juncture, the White House seems keen to float the comparison publicly.
From Press Secretary Robert Gibbs' briefing comes this:
"I think most of all, as I discussed in here and as you have heard the President say -- even here -- that he is looking for somebody with a full range and a diverse set of experiences in their background. And I think this is somebody like Justice Souter that brings an array of experience potentially to the job. So I think that the President sought somebody with that richness of experience and I think got somebody who meets that criteria."
Following up, Gibbs added: "Comparing her to Souter is probably, in many ways, somewhat coincidental. But, at the same time, I think the president recognized that being a prosecutor, being a private litigator, and being both a circuit and appellate court judge provides you with sort of a vast array of different legal experiences which makes Justice Sotomayor particularly compelling in this moment."