I don't think that he's alone in thinking that a Supreme Court judge should have sat on a bench before. Just because there have been others doesn't necessarily justify it.
It doesn't disqualify them either. As people have pointed out, it is hardly an anomaly that someone with no judicial experience has become a Supreme Court judge....ie Rehnquist. The lack of experience hasn't hindered Rehnquist's SCOTUS career.
I seem to recall in fact that a few Court justices had no legal background period. Now *that* would be worrisome only because the legal regulations, importance of SCOTUS, etc. have changed dramatically since the 1800s.
Making changes to the constitution has NOTHING to do with activist judges. It's the PROPER way to change the laws of the land. Activist judges create new laws with their rulings instead of following the ones already on the books.
That's your opinion. I happen to believe that an activist judge
1) seeks expansive rulings, especially when a more narrower, pragmatic opinion would have sufficed
2) rules based on their political preferences, irregardless of the law or the facts of the case
3) habitually overturns precedent and/or declares laws unconstitutional
in short, activism = unnecessarily broad, sweeping rulings, political/personal basis for judicial rulings, and consistently overturning precedent and/or declaring laws "unconstitutional".
this doesn't necessarily mean that a "new law" is activist, especially if previous rulings are non-existent, ambiguous, or contradictory. were judges upholding "separate but equal" doctrine activist considering 14th amendment's "equal protection" clause because treating people separately by race isn't equal? were judges striking down "separate but equal" activist because they overrode separate but equal even though the separate doctrine was discriminatory and against the equal protection clause?
the mere fact that precedent was overturned or a law was declared unconstitutional does not in and of itself denote "activism"