Emily Bazelon for NYT Magazine:

If Mr. Obama nominated a moderate and the Republicans who control the Senate refused to confirm him, would the country find itself in the throes of a constitutional crisis? I did a quick poll of five constitutional law professors on Saturday night, and the consensus was no. “The world won’t crumble,” as Bruce Ackerman, a Yale law professor, put it.

The government will still function in the interim, even if it is a long interim. The court can still decide cases. If it splits 4-4 (as it does every once in a while when one justice or another sits out a case), then the lower court ruling is upheld. That is likely in one major case this term. The court recently heard arguments in a significant challenge to the labor movementover the collection of dues by public-sector unions, and it looked like the plaintiffs would prevail; a tie, without Scalia, would keep the current system intact. Even a run of 4-4 rulings will not create chaos. The outcomes would be more likely to preserve the status quo, especially because the court could wait to take cases until it can resolve them with a clear majority.

But even if a Republican refusal to confirm a nominee by Mr. Obama would not bring the government to a stop, it would still be a major political struggle — a “stress test for our system of separation of powers,” said Richard Hasen, a University of California, Irvine, law professor and author of the new book “Plutocrats United.” In 2004, Mark Tushnet, a Georgetown University law professor, wrote an article about “constitutional hardball,” which he defines as legal and political moves that are “within the bounds of existing constitutional doctrine and practice but that are nonetheless in some tension with existing pre-constitutional understandings.”