Final answer:
Minor parties can play a spoiler role in elections by drawing votes away from major parties and potentially altering the outcome, serving as safety valves for voter discontent and keeping major parties in check.
Step-by-step explanation:
The spoiler role that minor parties play refers to their potential impact on election outcomes, wherein they draw votes away from major parties, possibly changing the overall result. An example of this is the 2000 Bush v. Gore presidential election, where Ralph Nader and the Green Party likely drew votes that might have otherwise gone to Gore, contributing to Bush's victory. While third parties rarely win significant office, they are considered important for representing alternative views and acting as safety valves for voter dissatisfaction with major parties, according to analysts like Rosenstone. Their presence helps keep major parties accountable, introduces new issues into the political conversation, and may serve to influence the policies of the dominant political entities.