All of these titles are located on the 2nd floor.
These titles are located on the 3rd floor:
Museum of the Moving Image: The Living Room Candidate: Presidential Campaign Commercials, 1952-2016
New Repbulic's 2016 Campaign Ad Archive
Political TV Ad Archive: 2016 political ads
Politifact: 10 most aired political ads, fact-checked: 2016 campaign
Time: Watch the 10 Most Notable Campaign Ads of 2016
New York Times Historical Archive 1851-5 years ago, and the New York Times 1980-present can display images from print campaigns. Go to Advanced Search to select Advertisement from Document type.
Google images and Youtube are also good places to search for images and video of campaign ads.