Final answer:
PACs primarily contribute to incumbents because they value their power and ability to influence policy. Corporations and other interest groups use both PACs and super PACs to support their interests, with PACs being limited in individual contributions and super PACs being restricted from contributing directly to candidates.
Step-by-step explanation:
PACs, or political action committees, tend to donate most of their funding to incumbents. Many large corporations have their own PACs, necessarily focusing on interests related to their industries, and they typically value the power and influence that incumbents hold. For instance, historical evidence like the case of Enron shows that corporations tend to support those in a position to make decisions beneficial to the company, as many members of relevant committees received contributions from Enron or its associated accounting firm, Arthur Andersen.
There is a distinction between traditional PACs and super PACs in terms of financial contributions and limitations. Whereas PACs are restricted in the amount of money they can contribute to individual candidates or national party organizations, super PACs can accept unlimited contributions, but they cannot contribute directly to candidates. The impact of these donations by PACs and super PACs on the electoral process is significant, influencing the election outcomes and subsequently policies and legislation, which reaffirms the preference of many interest groups to support candidates who are already in power, such as incumbents.