Two of your last three paragraphs have got me to thinking a whole lot, President Scott.
Nixon, Ford, Reagan, both the Bushes, and even Trump, all nominated justices that displeased the conservative base at one point or another. Earl Warren, who oversaw the greatest expansion of civil rights and liberty protections, was a Republican. Byron White, who dissented in Roe, was appointed by JFK.
Going in chronological order, Earl Warren was certainly from the liberal wing of his party. Two of the four times he was elected statewide in California he was the nominee of both the Republican and the Democratic parties, thanks to California's cross-filing law at the time. He despised Richard Nixon, and he certainly didn't vote for Nixon any of the three times he was the GOP nominee for President. It's highly doubtful he would have voted for Goldwater, either. Eisenhower only appointed Warren as political payback: Warren dropped out of the 1952 presidential race and endorsed Eisenhower, and thus Eisenhower owed Warren a huge favor, and giving the Chief Justiceship to him was Eisenhower paying Warren back. Of course, Eisenhower eventually came to strongly regret that appointment, and considered it to be the biggest mistake of his presidency. Warren was certainly a very result-oriented Chief Justice; he may not have ever consciously thought of himself as a "legal realist," but he certainly found William O. Douglas's always-liberal, choose-your-result-first-and-figure-out-the-legal-reasoning-later jurisprudence to be quite attractive. One admirer of Warren said he was "born to act, not to muse," which, decades later, made Robert Bork respond by saying that that was "rather an odd compliment for a man whose job is intellectual." Prof. Alexander Bickel once wrote,
When a lawyer stood before [Earl Warren] arguing for his side of a case on the basis of some legal doctrine or other, or making a procedural point, or contending that the Constitution allocated competence over a given issue to another branch of government than the Supreme Court or to the states rather than the federal government, the chief justice would shake him off saying, "Yes, yes, yes, but is it (whatever the case exemplified about law or about the society), is it right? Is it good?" More than once, and in some of its most important actions, the Warren Court got over doctrinal difficulties or issues of the allocation of competences among various institutions by asking what it viewed as a decisive practical question: if the Court did not take a certain action which was right and good, would other institutions do so, given political realities? The Warren Court took the greatest pride in cutting through legal technicalities, in piercing through procedure to substance. (Bickel, The Morality of Consent, (1975), pp 120-121.)
Regarding Byron White, I found a fascinating quote about him in a biographical book about Hugo Black. The quote was attributed to Harvey Poe, who was co-director, with White, of Citizens for Kennedy in 1960. "Jack thought he'd be a great liberal. But Byron has a quirky streak. He likes it that nobody really knows him or his views. He enjoys being individualistic." (Roger Newman,
Hugo Black; A Biography, (1994), p. 518.) White did end up becoming a moderate and unpredictable member of the Court. White tended to be most conservative on issues that pertained to the rights of criminal defendants, but he tended to be liberal on several Equal Protection issues, often supporting some of the Warren Court's most innovative ways of using the EP Clause.
Next, when President Nixon appointed Burger, Blackmun, Powell, and Rehnquist, when President Reagan appointed O'Connor, Scalia, and Kennedy, and when President G.H.W. Bush appointed Souter, the common theme running through those eight nominations was that those Presidents were looking for someone who would be "conservative" about the rights of criminal defendants. Nixon, Reagan, and the elder Bush were sick of the Warren Court's expansive treatment of those rights, and they wanted people on the Court who would whittle away at (but not outright overturn, per se) the Warren Court's landmark decisions in that aspect of constitutional law. G.H.W. Bush's appointment of Clarence Thomas was based solely on one consideration: he wanted a black person who was opposed to affirmative action. Nothing else mattered than that one issue. On the other hand, President Ford did not have any political motivation in choosing to appoint John Paul Stevens to the Court; he wanted to find what he could consider to be one of the best jurists in the country, and Ford should be commended for making that choice for that reason. (I tend to think of Stevens as the best Justice in the last fifty years of the Court, and I would rank him among the best of all time if it weren't for the fact that Stevens went along too much with the rest of the Court in rendering interpretations of the Due Process Clause and the Equal Protection Clause that were far beyond what those clauses were intended to mean.) On yet another hand, I am far from clear what was going through G.W. Bush's mind when he chose to appoint Roberts and Alito. GWB claimed he simply wanted to appoint people to the Court who would objectively interpret the law, but his statement about that clearly rings like hypocrisy -- in the classic sense that hypocrisy is an homage that vice pays to virtue. Bush's words were virtuous, but he didn't fulfill what he said.
Democratic presidents will predictably appoint liberal-leaning judges just as Republicans will appoint conservatives, but the Court as of late has erred on the side of caution and compromise in order to preserve its legitimacy. This, at least, is John Roberts' main concern. And while that may be a political strategy, it is not for any ideological cause.
Okay, but any political motive for why someone renders an interpretation of law is likely going to result in a misinterpretation of law, rather than an accurate interpretation. I
do have a lot of respect for how Roberts and Kennedy sided with the liberal members of the Court in
King v. Burwell, and I'm sure they rendered an interpretation of Obamacare that fulfilled what Congress intended to accomplish, even though that interpretation was not at all based on "textualism." But just last year, Roberts and the liberals sided with Gorsuch in
Bostock v. Clayton County, based on legal reasoning that was purely "textualism" and which certainly went beyond what Congress intended. So Roberts and the liberals are fair-weather friends of both originalism and textualism -- correctly using originalism in
King v. Burwell and incorrectly using textualism in
Bostock. To me, the "legitimacy" of what the Court does ought to be based on the accuracy of their interpretation of law, based on the intent of the law-makers, not with whether or not it pleases the current political atmosphere, and thus keeps up the veneer of ideological moderation.