There's also the fact that RAT presidents haven't had the opportunity to pick nearly as many SCOTUS judges in recent years. Carter got 0, Clinton and Obama got 2 each. So that's a total of 4 RAT judges in the last 40+ years, and their track record was a perfect 4-0 in getting ideological leftists.
If we looked at lower court federal judges, I'd be willing to bet Obama or Clinton "accidentally" appointed a judge who turned out to be far more conservative than they expected.
Supposedly Illinois Supreme Court justice Anne Burke (wife of a powerful Chicago Democrat alderman) was on Obama's short list. Had she ultimately been his nominee, I think she would have turned out to be a Byron White type judge who issued some pretty good rulings. She's been surprisingly good for a partisan Chicago RAT on the Illinois Supreme Court.
The bottom line is that its impossible for any President to tell how judges will vote after a lifetime appointment to a federal court. All the more reason why I'm in favor of term limits and mandatory retirement ages for federal judges, and vehemently against Senators rubber-stamping ANY judicial nominee the moment the candidate is announced.
Hey, can we count Stevens as an honorary Carter pick ?