“What we see over the broad sweep of American history is power concentrating within the presidency — and Congress, in part because of the party system, really does not seem competent to stand up to the president. But the Supreme Court can. So in the terrorism cases, in particular, the Supreme Court rejected an extraordinarily dangerous theory of executive authority which basically was, if the president thinks something is necessary for national security purposes, he can do it and no one can stop him. He can seize an American citizen within the United States, such as José Padilla, arrested in Chicago, and detain him indefinitely without access to a lawyer and interrogate him in any method he pleases, and no one can stop him.”
“If you don’t have the Supreme Court, who’s going to say no to that? Well, Congress might, if they’re controlled by the other party and they really have the will to do it. But if the president’s party has meaningful power in Congress, Congress is not going to stop the president, so you really do need an independent branch of government that is not as directly affected by the party system, which is the great virtue of the Supreme Court, I think. So a slightly broader way of putting this is: Our system was designed with separation of powers as the means of protecting individual liberty. Separation of powers between the president and Congress doesn’t work very well any more because of the party system. The party system has really affected Congress’s ability to check the president. The Supreme Court remains a meaningful check, and for that reason, if nothing else, it’s very important.”