What major factor led to the change in the original electoral college?

The major factor that led to the change in the original electoral college is the development of political parties. Initially, the electoral college was designed to be a nonpartisan body, primarily composed of electors who would exercise their judgment to select a president. However, as political parties emerged in the early years of the Republic, the dynamics of the electoral process shifted significantly.

Political parties organized their members to conduct campaigns, create platforms, and mobilize voter bases which subsequently changed the functions of the electoral college. The nomination of candidates became primarily a party-focused effort, and the electors began to represent their respective parties rather than acting solely on personal judgment.

This shift in the role of the electoral college mirrored the changes in American politics, where party affiliation became a critical factor in elections. As a result, the electoral college evolved into a mechanism that largely reinforced the two-party system, which continues to shape U.S. elections today. The historical context of how political parties came to dominate the electoral process illustrates the importance of this factor in the changes observed in the electoral college structure.