Final answer:
The main objective of political parties in presidential debates is to explain and promote their party platforms, advocating for specific policy positions to the voting public.
Step-by-step explanation:
The primary goal of political parties in televised presidential debates is to explain party platforms. During the debates, candidates promote their party's policies and positions on various issues, which are known as planks within their broader platform. For example, one party may advocate for women's choice in reproductive health while another party may push for restrictions in this policy area. Debates provide a political forum for candidates to convey their message to the voters, highlighting why they should be the preferred choice, and often involve preparation and strategy to present their views effectively and memorably under the pressure of a national audience.