Here’s a quote from the introduction to Statutory Interpretation: General Principles and Recent Trends (Sept. 24, 2014 97-589):

Interpretive methods that emphasize the primacy of text and staying within the boundaries of statutes themselves to discern meaning are “textualist.” Other approaches, including “intentionalism,” are more open to taking extrinsic considerations into account. Most particularly, some Justices may be willing to look to legislative history to clarify ambiguous text. This report briefly reviews what constitutes “legislative history,” including, possibly, presidential signing statements, and the factors that might lead the Court to consider it.

— Joe