Answer :
Final answer:
PACs primarily donate to incumbents due to incumbents' higher chances of winning, influence from holding key committee positions, and established voting records, which make them more attractive and reliable investments for PACs.
Explanation:
Most PAC money goes overwhelmingly to incumbents because incumbents are more likely to win reelection, have valuable Washington experience, and are known commodities with a voting track record on national issues. Incumbents, being current holders of office, tend to receive a significant financial advantage from PACs, often resulting in a substantial incumbency effect. Reasons for this include the safety and predictability of investing in someone who has a proven record of winning and alignment with the organized interests of the PAC, the influence that incumbents may hold through positions on key committees, and name recognition which requires challengers to spend heavily to become competitive.