The big question when it comes to the Supreme Court...

and their upcoming rulings on Proposition 8 and the Defense of Marriage Act seems to be, will the court rule 5-4 in favor of same-sex marriage rights, or 5-4 against same-sex marriage rights.

The swing vote is in the sure hands of Justice Anthony Kennedy and proponents of same-sex marriage rights should not worry.  In the end he will vote to interpret the Constitution as providing marriage equality as a right. 

Why do I make this prediction?  History.  Specifically the majority opinion that Justice Kennedy authored in the landmark ruling Lawrence v Texas where the court struck down a Texas sodomy law and invalidated anti-sodomy laws in 13 other states.  The rulings in the Prop 8 and DOMA cases will probably be the last landmark rulings on gay rights that will be decided by the Court before Kennedy retires.  His legacy will probably be the authoring of those two majority opinions.

One of the issues that will undoubtedly arise during oral arguments for these cases are how other nations have chosen to protect marriage equality rights.  In the majority opinion Justice Kennedy wrote in Lawrence v Texas, he cited a 1981 decision of the European Court of Human Rights.  In this decision the Court overruled Bowers v Hardwick, a 1986 decision where the constitutionality of sodomy laws was upheld.  When Justice Kennedy wrote his majority opinion in Lawrence, he went back to the dissent that had been written in Bowers by Justice Stevens and said that Bowers was wrong then and now. 

But the real reason I'm writing about this case isn't how I expect the Court to rule or that I'm convinced that Justice Kennedy's swing vote will finally end the debate over whether or not homosexuals are entitled to marriage equality.  They are.  The issue is the ideological divide of the court.

When we know with almost 100% certainty how eight of the nine justices will vote on an issue before the issue reaches the point of oral arguments, ideology has supplanted interpretation as the driving factor behind how the Court rules.  It highlights just how important it is for there to be the narrowest possible divide between conservatives and liberals in the Court's composition.

Four of the nine present justices are more than 70 years old.  One is 79 (Justice Ginsburg) and two are 76 (Justices Kennedy and Scalia).  In the next four years there is a good likelihood that President Obama will make at least one appointment to replace one of these three.  He may end up making three, possibly four.   While past justices have served well beyond the age of 80 (Justice Stevens retired in 2010 at the age of 90), I wouldn't be surprised to see more than one justice choose to retire during President Obama's second term.

I doubt it will be Justice Scalia.  He will hold out hope that a conservative will be elected to the Presidency in 2016 and that person can appoint a conservative replacement for him when he retires.  He shouldn't have to wait.  If a justice chooses to retire, the sitting President should consider that justice's ideology in choosing their replacement.  That hasn't been the pattern in the past but it would be a smart thing to do in the future.

Then again, the political philosophies espoused by justices in their tenure on the court hasn't always worked out as intended.  Take the case of Justice Harry Blackmun, a lifelong Republican who was expected to be a conservative when nominated to the Court by President Nixon.  Initially voting with the conservative side, his later votes and opinions were those of a member of the Court's liberal side.

So those of us who support marriage equality should not worry how the Court will rule.  But all of us should worry about who will ultimately be nominated to the Court in the future.