Good points, though I read Obama's "heart" comment as a meaningful point: he was responding to Roberts's silly "umpire" analogy by saying that not all cases are a simple matter of "getting it right" with technical application of the law -- that a Justice's philosophy does matter. He said "heart" rather than "philosophy" just because politicians do more emotion-speak than we law profs do.

And there is precedent for a presidential candidate sayign whom he'd like to appoint: Bill Clinton, running in 1992, said he'd like to appoint Mario Cuomo (who thentook himself out of contention when the White House specifically asked him in 1993 if he was interested in replacing Justice White).

In Texas, judges are elected, and the system gets a lot of criticism (much of it warranted) for that. However, I really don't see the difference between the U.S. population electing S/C justices and the U.S. population electing a President based on who he says he will nominate as a S/C justice (or who we think the candidate will nominate). I suppose that one of the evils of electing judges is that because judges must run for re-election, they may rule according to the preferences of their party affiliation. Supreme Court justices are free to rule according to their own principles once confirmed. Until that point, however, they seem to be basically elected.

By not completely pre-committing to individuals, the would-be president (1) retains some flexibility in negotiating with powerful senators over preferred picks, and (2) prevents opponents from building up their oppo-research files months if not years in advance.