Final answer:
Ideological third parties focus on specific causes, while splinter parties are offshoots of major parties.
Step-by-step explanation:
Ideological third parties tend to focus on promoting a single cause or a specific set of related causes. They may revolve around a controversial issue or advocate for extreme ideological positions. For example, the Libertarian Party is known for its emphasis on personal liberties and limited government.
On the other hand, splinter parties are offshoots of a major party. They emerge when a faction within a party breaks away due to ideological differences or disagreements with party leadership. For instance, Strom Thurmond's States' Righters, which splintered from the Democratic Party, focused on states' rights in the 1948 presidential election.
While ideological third parties promote specific causes, splinter parties result from divisions within larger parties.