What historical and political changes in society have influenced presidential nominating methods?

Historical and political changes, such as the expansion of suffrage and the rise of the progressive movement, have significantly influenced presidential nominating methods in the United States. The shift from party elites selecting candidates in smoke-filled rooms to more democratic processes, like primaries and caucuses, emerged in response to calls for increased voter participation and transparency. Additionally, the Civil Rights Movement and subsequent legislation further democratized the nomination process by ensuring broader access for diverse populations. These changes reflect a broader societal demand for accountability and inclusivity in the political sphere.