Available Online, 1780, Political Cartoons | Library of Congress (loc.gov)
The Library of Congress’s collection of political cartoons, which contains documents from before the publishing of the Declaration of Independence, provides a well-rounded view of public opinion surrounding presidential candidates and elected officials.
This database from the University of Indiana houses political cartoons related to Presidential elections from 1789 to 1976. A particularly interesting set came from the 1832 election, where Henry Clay and his supporters depicted Andrew Jackson as a king abusing his veto power. The famous “King Andrew the First” cartoon came from this election, as well as the first depiction of Uncle Sam in a political cartoon.