With the ObamaCare ruling expected within the hour, it’s time to start thinking about what the political impact of the ruling will be. There will be plenty of time to sort out which side is hurt based on whatever the outcome turns out to be, but it’s also worth noting that whoever takes office in 2013 will have a chance to have a major impact on the Supreme Court for years to come:

WASHINGTON — Justice Ruth Bader Ginsburg is not known for delivering laugh lines. But she drew chuckles from a group of liberal lawyers not long ago while recalling how Justice Elena Kagan, 52, had suggested during an oral argument before the Supreme Court that people born before 1948 were old.

“Next year I will turn 80, God willing,” Justice Ginsburg said. “ ’I’m not all that old,’ I told my youngest colleague.”

Justice Ginsburg is the eldest member of a court that includes four justices in their 70s, making it among the oldest courts since the New Deal era. Its decisions during this historic “flood season,” as Justice Ginsburg described the end-of-term rush, are likely to make the panel — and the tenure of some of the justices — a significant issue in the presidential campaign.

On Monday, the court’s ruling in an Arizona immigration case delivered a partial victory to the Obama administration but also deeply disappointed some Latinos by upholding a requirement that police officers check the immigration status of anyone they stop if they suspect that the person is in the country illegally.

On Thursday, the court is expected to announce its decision on President Obama’s health care law, one of the most consequential cases in decades. This fall, the court will take on an affirmative action case that could end preferential treatment at public universities, and it might hear a case involving same-sex marriage.

The winner of the race for president will inherit a group of justices who frequently split 5 to 4 along ideological lines. That suggests that the next president could have a powerful impact if he gets to replace a justice of the opposing side.

“This election could shape the court for decades to come,” said Nan Aron, president of the Alliance for Justice, a liberal advocacy group.

It is, of course, impossible to predict when a vacancy will occur. (Justice John Paul Stevens spent 35 years on the court and retired at 90, while Justice Robert H. Jackson, who served in the 1940s and 1950s, died of a heart attack at 62.) A 2006 study in the Harvard Journal of Law and Public Policy found that the average retirement age for justices was 78.7.

Justice Ginsburg, a stalwart of the court’s liberal bloc, has been treated for pancreatic cancer. Justice Antonin Scalia, the court’s most visible conservative, is 76. Justice Anthony M. Kennedy, frequently the swing vote, is 75. And Justice Stephen G. Breyer, like Justice Ginsburg a Democratic appointee, is about to turn 74.

Indeed, for the past year or so some on the left have been expressing the opinion that Justice Ginsburg should have retired while Obama had a chance to appoint a replacement due to the danger that she would end up having to step down while a Republican is President, just creating an opportunity to solidify an already strong conservative majority on the Court. Harvard Law Professor Randall Kennedy expressed the same opinion in a piece in the New Republic about a year ago, but Ginsburg has made it clear that she had no intention of stepping down. Accordingly to some speculation, Ginsburg would like to stay on the Court at least as long as Justice Louis Brandies did, which would mean that she’d be there until at least 2015 when she would be 82 years old. While she, and the other Justices, all appear to be health at the moment it’s worth noting that Ginsburg has been previously treated for cancer so the possibility of involuntary retirements is certainly out there with so many justices over 70.

Once it takes both sides time to digest whatever it is that the Court does today, I would expect that we’ll see this become at least a side issue in the Presidential Election. If the mandate, and perhaps the entire law, is overturned then you can expect to hear Democrats argue that the nation cannot afford to let Mitt Romney shape the destiny of the Supreme Court for the next two or three decades, and they’ll likely tie into the “war on women” argument by bringing up the possibility of the Court putting further restrictions on abortion rights and the like. If the Court ends up upholding the law, then Republicans will likely argue that it’s a sign that the nation needs more Justices who follow the “original intent” of the Constitution. Indeed, regardless of what the result is it would be fairly easy for either side to work the Supreme Court into their election rhetoric. It won’t be the most important, and certainly not the decisive issue in the election, but the fact that the President who takes the Oath of Office on January 20th, 2013 could have the opportunity to appoint as many as four new Supreme Court Justices during their time in office is something that neither political party is going to let the voters forget.