Plot: Mackenzie Allen has a lot on her plate -- she has twin teenagers, a 6-year-old at home and an ambitious husband at the office, and she is about to become the first female president of the United States. Before that happens, however; Mackenzie, who serves as vice president, has to decide whether or not to go against the dying wishes of the current president, who has asked her to step down and let someone "more appropriate" fill his shoes in the Oval Office