Final answer:
Special interest groups influence campaigns mainly through their financial contributions to candidates with aligning views, enabling them to have substantial sway over political outcomes. Their relationships with political parties fluctuate, affecting their policy influence. Despite their power, democratic systems provide counterbalances to mitigate these influences over time.
Step-by-step explanation:
Special interest groups have more influence in campaigns primarily because they can donate money to candidates who agree with their views. This practice gives these groups leverage over political candidates as they are considerably funded and well-organized, exerting a disproportionate effect on political outcomes. Moreover, special interests develop close relationships with political parties, and their influence varies as these parties gain or lose power. This dynamic means that in close elections or periods of governance, their voice and concerns can become focal points for legislation and policy-making. However, this financial influence has also sparked debate about the role and regulation of such groups in democratic systems given their potential to sway political decisions that affect the broader public.
Interest groups support candidates sympathetic to their views in hopes of gaining access to them once they are in office. They use resources like PACs and super PACs to channel funds to political campaigns, with the expectation that these contributions will result in favorable policy decisions. Despite the advantages that interest groups have due to their funding and organization, democratic institutions inherently have mechanisms which provide a balance, allowing for an ebb and flow of different political interests over time.