West Codenotes (wcn) provide a way to find modern cases (older cases won't contain this enhancement) that have held statutes unconstitutional. West Codenotes appear between the West Headnotes and the text of an opinion in cases that "impact the constitutionality or validity of a statute." This field is a searchable field on Westlaw, but it is not listed with the other searchable fields.

You can find examples of cases in which courts have found statues to be void for vagueness. Select the database ALLCASES and type wcn(unconst!) & sy,di(vague).

You can also search for cases in which courts have found state laws to be preempted by ERISA. Select the database ALLCASES and type wcn(preempt!) & sy,di(e.r.i.s.a. "employee retirement income security act").

Note: Using sy,di in your search statement restricts the search to the synopsis and digest fields that contain editorial summaries of the issues in a case. This way you avoid retrieving cases containing "irrelevant occurrences" of your search terms.