In the late 1990s increasing public concern about the role of money in politics led to

In the late 1990s increasing public concern about the role of money in politics led to ''attempts to reform campaign financing''

Explanation:

Unlike many other industrialized countries, election campaigns in the United States are heavily funded by individuals, corporations as well as lobbying groups.

By the 1990s so much private money was involved in politics that many were concerned about the power these donors held. Since it was clear that the largest donors would be able to swing many laws and regulations in their favour.

A concentrated effort was eventually developed to reform campaign financing, including transparency into how much was paid by who.