Final answer:
PACs generally contribute money to members of Congress to gain access to policymakers, not to buy votes or install preferred challengers in office. They operate within legal donation limits, whereas super PACs have no contribution caps but cannot give directly to candidates.
Step-by-step explanation:
When Political Action Committees (PACs) contribute money to members of Congress, they are usually seeking access to policymakers. This is because PACs, and particularly super PACs, collect funds and distribute them to candidates or political groups with the hope of gaining a line of communication once those candidates are in office. While PACs are limited in the amount they can directly donate to individuals or party organizations, super PACs can raise unlimited sums for advocacy but must operate independently of the candidates' campaigns. The intent is often to have the ability to present their information and views to lawmakers on policies that affect their interests and to potentially influence lawmakers' positions or votes on specific legislation.
However, PACs do not attempt to literally buy opposing legislators' votes or to create a more pluralistic Congress, nor do they primarily seek to install a preferred challenger in office. It is inaccurate to suggest that PACs contribute with the aim of literally purchasing votes, as this would be illegal.
Lobbyists from these groups also provide valuable information to lawmakers, aiding them in making more informed decisions on complex policy issues. Despite critiques that suggest monetary contributions to political candidates may lead to conflicts of interest, the fundraising efforts by interest groups are also considered by some to be a form of free speech, as per the Supreme Court's interpretation.