Final answer:
True, splinter parties are minor parties that have broken away from the major parties. They serve as outlets for voter discontent and can influence the political spectrum, although they rarely win major elections.
Step-by-step explanation:
Splinter parties are indeed minor parties that have split away from one of the major political parties. A classic example would be Teddy Roosevelt's Progressives who were a splint off of the Republican Party in 1912. Other instances include Strom Thurmond's States' Righters and George Wallace's American Independents, which both emerged from conservative segments of the Democratic party in the southern United States.
While these minor parties and others, such as the Socialist Party or the Anti-Masonic Party, have occasionally cropped up through history, they typically do not win major elections. Nevertheless, they serve a vital role in the political process. Political analysts posit that these parties act as 'safety valves' for voter discontent, allowing an outlet for those dissatisfied with the options provided by the major parties.
Third parties can also affect the political landscape by causing major parties to lose votes, a scenario often referred to as playing the 'spoiler' role. Furthermore, they may contribute to wider ideological spread and sometimes complicate political decision-making, a situation called hyperpluralism. Despite the challenges faced by third parties, including resource limitations and lack of media coverage, they have occasionally influenced major shifts within the U.S party system and public policy.