Sonia Sotomayor, President Obama’s nominee to fill a vacancy on the US supreme court, has been recommended by the Senate Judiciary Committee on a vote of 13 to 6. Barring some utterly unforeseen revelation, she will be confirmed by the full Senate next week.

The vote, however, was mostly along party lines; only one of the committee’s seven Republicans voted for the recommendation. Sotomayor will have to rely almost entirely on the votes of the president’s party — just as did the last nominee, Samuel Alito, who was confirmed in 2006 on a vote of 58-42, with all but four Democrats voting against.

So there is an element of truth to the suggestion by Anne Davies in this morning’s Age that Republican opposition to Sotomayor is driven by “desires for political payback and gamesmanship.” But to present this as a game of tit-for-tat that the Democrats started ignores some vital features of the context.

What made the Alito nomination so controversial was that it threatened to change the balance of power on the court: he was replacing Sandra Day O’Connor, a moderate conservative who, although voting to make George W Bush president in 2000, had prevented the court’s opinions from tilting too far to the right, especially on social issues such as abortion. The advent of Alito promised a more reliable conservative majority.

Sotomayor, however, will replace David Souter, who (despite being appointed by a Republican, Bush Sr) has been a consistently liberal voice. Obama will not get an opportunity to change the court’s direction unless one of the four strongly conservative judges (Antonin Scalia, Clarence Thomas, Alito and chief justice John Roberts) should depart — which seems unlikely in the near future.

In the absence of that sort of ideological shift, Democrats have not shown such a strongly partisan bent in the past: Roberts, who replaced the conservative William Rehnquist, was confirmed 78-22. Scalia and O’Connor were confirmed almost unanimously, as was Anthony Kennedy, another of the majority justices in Bush vs. Gore. So were Bill Clinton’s two nominees, Ruth Ginsburg and Stephen Breyer (See the details here).

The opposition to Sotomayor also differs in quality from what Alito faced: the vein of racism underlying Republican rhetoric has been unmistakable. Despite her qualifications, the argument has been more about gender and ethnicity than judicial principles. But even that is to some extent incidental; the overwhelming reality is that this is a GOP caucus determined not to support Obama on anything.

It’s all reminiscent of the Clinton impeachment, which Republicans all but admitted had nothing to do with the actual (trivial) charges but was payback for the removal of Richard Nixon.