As stated in PDC Interpretation 91-03
from the Public Disclosure Commission (PDC)
It is a normal and regular function of a public library to obtain and provide public access to campaign brochures, fact sheets, voters and candidates pamphlets and similar documents which provide information regarding election campaigns.
Any library which chooses to display campaign material must provide equal opportunity to both proponents and opponents of any ballot measure or to all candidates. Preferential treatment may not be provided to one side over another or to one candidate or political group.
If supporters of one side of an issue or a candidate ask that material be displayed, library employees must make a good faith effort to obtain material from opposing or competing groups and make those materials available in library facilities.
There is no obligation on the part of libraries to serve as a distribution point for campaign materials.