Amid all the partisan gridlock in Washington, there's one institution the next president is likely to have a major say in shaping: the Supreme Court.
Depending on which justices -- if any -- vacate their seats in the next four years, their replacements could affect the ideological balance of a court that generally trends conservative, with 76-year-old Justice Anthony Kennedy, appointed by President Reagan, the most frequent swing vote.
Depending on who is president and which justices leave, the court's approach to cases involving environmental disputes could shift, some experts say. The election will also affect who gets nominated to judgeships around the country, including courts like the U.S. Court of Appeals for the District of Columbia Circuit and the San Francisco-based 9th U.S. Circuit Court of Appeals, which hear a large number of environmental cases.
Most legal observers think the most likely Supreme Court departee would be Justice Ruth Bader Ginsburg, now 79, who is one of the four solidly liberal members of the court. Aside from Ginsburg and Kennedy, the other justices over the age of 70 are conservative favorite Antonin Scalia, 76, and Stephen Breyer, 74, a moderate liberal.
Who decides to leave voluntarily would, of course, be determined in part by who wins the presidential election. Many observers believe, for example, that Ginsburg would almost certainly retire if President Obama were to win re-election. By the same token, Scalia and Kennedy might be more inclined to consider their options if Republican Mitt Romney were to win.
What would be a game-changer is if a conservative were to retire during an Obama second term or if a liberal were to leave under a President Romney.
"The stakes could hardly be higher," said Carrie Severino, chief counsel of the Judicial Crisis Network, a conservative advocacy group.
Obama could potentially have "an incredible impact" on the court if he wins a second term, she added, bearing in mind that the president has already appointed two justices, Sonia Sotomayor and Elena Kagan. Neither significantly altered the ideological balance of the court, but both are in their 50s and could serve long tenures.
Liberals picture their own nightmare scenarios if Romney wins the election.
People for the American Way, a left-leaning advocacy group, recently published a report warning that a "Romney court could leave a scorched earth" when it came to handling environmental cases.
The Supreme Court does not generally hear a huge number of environmental cases. This term, for example, the justices have so far decided to hear two Clean Water Act cases and two property rights cases that have environmental implications.
But sometimes, the cases can be huge, such as the 2007 decision in Massachusetts v. EPA, in which the court held on a 5-4 vote that greenhouse gas emissions could potentially be regulated under the Clean Air Act.
In a similar vein, the court is likely to be asked sometime in the next 12 months to intervene over the Obama administration's greenhouse gas regulations, which were upheld by the U.S. Court of Appeals for the District of Columbia Circuit (Greenwire, June 26).
For Patti Goldman, vice president of litigation at Earthjustice, the main concern has been "tremendous judicial activism" from conservative judges in recent years, which she fears would continue under a Romney administration.
She sees less deference to government "but more influence of corporate litigants" in environment-related cases.
People for the American Way's report focuses on Chief Justice John Roberts' dissenting opinion in Massachusetts v. EPA, in which he argued that states did not have standing to pursue their claim that the federal government could regulate greenhouse gases under the Clean Air Act.
"In short, by replacing one of the liberal justices with a conservative, the ability of the states to force the EPA to regulate greenhouse gases would probably vanish sooner rather than later," the report says.
Such colorful language may be overstating the impact of a nomination, according to Andrew Grossman, a lawyer with the Baker Hostetler law firm who has represented states challenging environmental regulations.
He noted that with environmental law, "change is at the margins," meaning it takes many years for trends to play themselves out.
Environmental law is also notoriously complex, often turning on the question of whether a particular party has standing to challenge a particular regulation, which means that it can be difficult to determine which way any one judge will rule, Grossman said.
"It doesn't always break down easily on party lines," he added.
A subtle shift
The way in which potential vacancies could affect the Supreme Court, depending on who gets to nominate the replacement, is a popular parlor game within the Washington legal community.
There are many potential permutations, but the simplest -- and least likely to change the ideological balance of the court -- would be if Ginsburg were to retire during a second Obama term, likely to be replaced by a moderate Democrat.
At the other end of the scale, the most seismic change would be if Scalia were forced to resign, perhaps for health reasons, and Obama was able to pick his replacement.
Such a move would "flip the court," said Pamela Harris, a Georgetown Law Center professor who recently returned to academia after a stint in the Justice Department's Office of Legal Policy.
It would likely mark the biggest shift on the court since liberal icon Thurgood Marshall was replaced by the ultra-conservative Clarence Thomas in 1991, she added.
But as Severino noted, Scalia is unlikely to leave during a Democratic administration if he can possibly help it.
"I don't think he would want see someone appointed who would undo his work," she said.
If Obama were able to replace Kennedy, the shift would be more subtle but would likely be slightly leftward, experts predict.
Potential candidates for an Obama nomination might include Judge Merrick Garland of the D.C. Circuit, 9th U.S. Circuit Court of Appeals Judge Jacqueline Nguyen, or even California Attorney General Kamala Harris (D).
The possibility of Romney replacing Ginsburg with a Republican appointee would cement conservative control of the court. A Kennedy departure would also allow Romney to appoint a more reliable conservative who would not join the liberal bloc on some of the issues conservatives care about most, as Kennedy has done on the death penalty, on gay rights and on climate change in Massachusetts v. EPA.
"He really will be required by his party to appoint extremely conservative justices," Harris said.
Among potential Romney candidates are the likes of Brett Kavanaugh, the D.C. Circuit judge who authored the recent opinion that vacated the Obama administration's cross-state air pollution rule, Judge Sandra Ikuta of the 9th Circuit and Judge Diane Sykes of the 7th U.S. Circuit Court of Appeals.
One of the oddities of the Obama administration is that officials have not made judicial nominations a priority in the same way that the George W. Bush administration did.
Vacancies on the bench have actually risen since Obama took office in January 2009. He has also had fewer nominees confirmed than either Bush or President Clinton had at this stage of their first terms.
As a result, observers say, Obama has not had as great an impact on the judiciary -- despite his two Supreme Court appointments -- as he might have.
"There's been some weakness from the administration in terms of taking the issue seriously," said Caroline Frederickson, executive director of the progressive American Constitution Society.
For the Judicial Crisis Network's Severino, the administration's lack of focus was a welcome surprise.
If Romney wins the election, "I hope he would have taken note of what happened to President Obama," she said.
Georgetown's Harris predicts that, if Romney wins, Republicans "have got their list [of potential judicial appointees] and are ready to go" from day one, as Bush officials were in 2001.
There have been some ideological shifts on lower courts, if only slightly to the center due to the fact that most of the Obama nominees have been moderates rather than outspoken liberals. One of the biggest shifts was on the Richmond, Va.-based 4th U.S. Circuit Court of Appeals, which is now majority Democratic appointees.
But Obama has not had any impact on the D.C. Circuit, which hears the majority of challenges to environmental regulations. So far, the court has no Obama appointments despite the fact that there are currently three vacancies among active judges. The administration currently has two nominees, Sri Srinivasan and Caitlin Halligan, awaiting confirmation.
Baker Hostetler's Grossman stressed the importance of that court, noting that in addition to hearing many cases of national importance, it serves as a "bench team" for potential future Supreme Court nominees.
Thus, he would expect a President Romney to place particular emphasis on potential nominations to the D.C. Circuit and other lower courts.
"Republican administrations always place great emphasis on judicial appointments," Grossman said. "I don't think that would be any different under a Romney administration."