What is a political machine?

a political party that started at the turn of the century
an unofficial political organization that ran big cities
a popular machine used to make streetcars
an innovative political party run by the government

A political machine is an unofficial political organization that ran big cities.

Explanation:

A political machine is a system of unequal personal dependencies in political apparatuses between influential people and their clients.  In other words, it is a system that controls the political organization of a given territory, exercised through the political power of certain members of the public administration.

The political machine works unofficially through the awarding of offices, behind-the-scenes control and long-standing political ties within the framework of representative democracy.

they usually pass federal laws

and sometimes in the elections of the president