Final answer:
Factors that decrease a congressional incumbent's chances for re-election include poor community visibility, ineffective constituent services, and involvement in controversies. Strong name recognition, financial support, and effective use of state power are conversely factors that increase re-election chances for incumbents.
Step-by-step explanation:
Factors that do not typically enhance a congressional incumbent's chances for re-election revolve around actions and perceptions that do not endear them to their constituents or make a positive impact in their districts. For instance, an incumbent might suffer if they have a lack of visibility in the community, fail to address constituent concerns effectively, or are involved in scandals or controversies. Moreover, poor casework or constituent services, lack of legislative achievements, and a disconnect with district issues can significantly detract from their re-election prospects. In contrast, strong incumbency factors like name recognition, voting records, financial support from political action committees and interest groups, as well as the ability to use state power and resources to assist constituents, tend to increase their chances of holding onto their seats.