The National Archives has put up a page with a bunch of the more interesting internal DOJ memos John Roberts wrote as a young lawyer, and Chris Geidner has found one memo in particular that paints a fascinating picture of how Roberts views judicial decisionmaking and government institutions (or at least how he did when he was a young lawyer).

  The background of the 2/16/82 memo is that Roberts' boss, Attorney General William French Smith, was scheduled to give a speech to conservative groups. Roberts was tasked with coming up with ideas for how to respond to criticisms from conservatives that the Reagan DOJ was not conservative enough. The National Review and the Heritage Foundation had been criticizing DOJ for not not taking consistently conservative views in cases, and for helping to select Sandra Day O'Connor as a Supreme Court nominee. Roberts wrote a memo on possible responses to this criticism; in the course of the memo, he offers some interesting suggestions about the role of the Supreme Court and government more generally:

  A related criticism [conservatives have made about the Reagan DOJ] focuses on the screening and appointment of federal judges, highlighted by the O'Connor debate. The assertion is that appointees are not ideologically committed to the President's policies, again with particular emphasis on the social agenda.
  Here again I do not think we should respond with a "yes they are"; rather we should shift the debate and briefly touch on our judicial restraint themes (for which this audience should give us some credit). It really should not matter what the personal ideology of our appointees may be, so long as they recognize that their ideology should have no role in the decisional process — i.e., so long as they believe in judicial restraint. This theme has to be glossed somewhat, because of the platform, but we can make the point that much criticism of our appointees has been misdirected. Judges do not implement policy in the true conservative view of things, and the hot issues of today will not be those of ten or fifteen years hence, when our judges will be confronted with new social issues. Our appointments process therefore looks beyond a laundry list of personal views to ascertain if the candidate has a proper appreciation of the judicial role.
  We have been criticized [by conservative groups] for not following Reagan policy in the Grove City, North Haven, and ERA cases. Perhaps without naming specific cases, we can make the point that we must defend acts of Congress in the courts (ERA) and must enforce the laws as written, not rewriting them to comport with policy desires (Grove City, North Haven). This is the role of the Department in the constitutional system, and our conservativism believes in that system. Any other approach would be trying to use the courts to set policy, having policy set by the Executive rather than Congress (cf. Bob Jones), or inviting Congress or other intervenors to present the position of the United States in court.

  (emphasis in original)

  It's hard to read too much into this one memo, but to me it's consistent with the idea that Roberts is less a committed political conservative than a committed judicial conservative of the Harlan/Frankfurter school. If his views today are the same as they were in 1982, Roberts' conservatism is a conservatism that "believes in the system" of institutions, not one that pushes the law to reach conservative results. That's the sense I get from the memo, at least.