Final answer:
The political cartoon suggests that support in congressional elections in the United States is conditional and self-interested.
Step-by-step explanation:
The political cartoon suggests that support in congressional elections in the United States is conditional and self-interested (C).
The cartoon references the incumbency advantage, where incumbents in congressional elections win re-election up to 90% of the time. This advantage is attributed to factors such as name recognition, voting records, and the support of political action committees and interest groups. However, the cartoon implies that this support is not based on genuine public interest or the desire to serve the people, but rather on the self-interest of both the incumbents and the supporting groups.