From Harvard's corporate governance blog:
In a recent paper, Professors Lucian Bebchuk and Robert Jackson have extended Professor Bebchuk’s extreme and eccentric campaign against director-centric governance into a new realm—that of the Constitution of the United States. They claim that “serious questions” exist about the constitutionality of the poison pill—or, more precisely, “about the validity of the state-law rules that authorize the use of the poison pill.” It is likely, they argue, that these state-law rules violate the Supremacy Clause of the Constitution, and are thus preempted, because they frustrate the purposes of the Williams Act, the 1968 federal statute that governs tender-offer timing and disclosure.
Lipton et al. then go on to say some very nasty things about the Bebchuk and Jackson article.