My colleague Bryan Marshall and I have a new publication in Social Science Quarterly (March 2010) that examines the various conditions that explain the use of the presidential signing statement. In the paper, we looked at such conditions as divided government, federal election cycles, and whether the legislation was major or minor, and found that presidents seek any condition to provide the opportunity to move unilaterally. Interestingly we find that presidents are as likely to use the constitutional signing statement during periods of unified government as during periods of divided government.

For the time being, the article is available online at the Social Science Quarterly website.