At the VC, Prof. Lindgren has the following commentary on Roberts' comparison of judges to baseball umpires. Specifically he has an amusing anecdote of three different types of umpires. But he ends the post with the following:
Further, I have heard that in Major League Baseball, umpires are rated on how well they call balls and strikes and demoted (or at least influenced in their future calls) if they call balls and strikes poorly. I question whether the press provides a similarly effective role judging the performance of justices.
While Prof. Lindgren can question the effectiveness of the press (does this include bloggers?) to judge the judges, I don't see the relevance of this analogy. Umpires, though constantly under scrutiny by SportsCenter instant replay are NEVER officially evaluated by the media. If there is ANY evaluation of an ump's performance, it's through an internal mechanism within MLB. See, e.g., rules governing a game played under protest. Cue U.S. Court of Appeals and SCOTUS.
Although strong arguments can be made that the judges and justices on those courts are not checked by any internal mechanism, I think the threat of reversal by the SCOTUS over Court of Appeals judges is at least nominally as great a threat as MLB imposes on any Ump. The only problem is with the justices on Mt. Olympus. Ultimately, I don't know if this is what Prof. Lindgren meant, but the accountability is to the electorate (where the press assists the electorate perhaps?). As Justice Roberts' switch following the sweeping victory of FDR illustrates, there is ultimate accountability even on the part of SCOTUS justices. Anything more would require some serious amendments regarding life tenure and guaranteed salaries (though I suspect the latter is not much of a threat).