Every time a new nominee is put forth for the Supreme Court, there is a lot of opining about what it means for the country, whether the nominee will tilt the balance of the court, and, as in this post by Ross Douthat, whether there should be term limits or other mechanisms to make these nominations a little less momentous.
In the course of discussing term limits, Douthat quotes blogger Matt Yglesias as saying, "The most important consideration for the future of American law is not whether Justice Kagan turns out to be more like Breyer or more like Stevens, it’s whether the seventy-four year-old Antonin Scalia can stay in good health until there’s a Republican in the White House." This hits at the heart of the problem with the court, but it is not one I think can be solved by term limits.
The problem is this: the only reason that the decisions of the Supreme Court have not caused major problems in this country so far is that justices have had the courtesy to leave or get ill at a time when the current President would replace them with someone who would carry on their ideological torch. This has happened somewhat accidentally at first, with Republican presidents nominating justices that would turn out to be liberal. But since Jimmy Carter, we've had somewhat consistent back-and-forth between Democratic and Republican presidents, who have (with the exception of Souter), always nominated someone more or less on their 'team'. There are decisions that are unpopular with one side or the other, but the Court seems within the mainstream of American politics, more or less.
But what happens if, as an example, John Roberts and Samuel Alito are in a fatal car accident next week? Suddenly, the two Bush justices, who were supposed to be reliably conservative votes for decades, are wiped out, and Obama is going to pick their replacements. The Republicans can filibuster a hard-left liberal, but they have to let someone through. Now the court is six liberal votes (four of whom Obama picked, and will serve for a long time in all likelihood), two conservative votes (and one of them 74 years old) and Kennedy, whose 'swing vote' power is now meaningless. Even if the Republicans defeat Obama in 2012 and hold the presidency for the next 20 years, they might not get a chance to do more than replace Ginsburg and Breyer. And who knows, one or both of them may retire soon to ensure Obama replaces them, too.
A court of that composition would certainly never consider adjustments to Roe v. Wade, would likely strike down restrictions on gay marriage, may well curtail gun ownership rights, and would be inclined to extend and expand racial preferences. No matter how you feel about these issues, it is impossible to deny that not giving conservatives any recourse on a number of issues that matter greatly to them would strain the political system immensely. I once drafted a novel with the premise that assassinations on the Supreme Court precipitated the breakup of the United States. Hopefully that never comes to pass, but it is undeniable that the Supreme Court is not only our least democratic branch of government, it is the most unstable and unpredictable. It is thus a likely source of future instability in the country.