Incumbent governor Thomas McKean won a contentious election over the endorsed Democratic-Republican candidate, Speaker of the Pennsylvania House of Representatives Simon Snyder.

Although the Democratic-Republicans united behind the McKean ticket in each of the prior two election cycles, by 1805, the party had divided into moderate and radical wings.

The former sought to balance the political power of the traditional elite and the lower classes; this group additionally supported liberal economic policies.

Democratic-Republican newspapers were dominated by radical interests, and the press vociferously denounced McKean's support for strong executive and judicial power.

The governor formed a working alliance with the Federalists called "the quids" and began to purge radicals from appointed offices.