As Mackenzie begins the transition into the office of President, she has to select a Vice President, a situation in which Nathan Templeton tries using to his advantage. Mackenzie's daughter, Rebecca, faces a crisis when her diary goes missing, which contains information about her mother that could hurt her.

Faced with her first national crisis - the death of nine DEA agents in Latin America - Mackenzie shows strength and resolve in dealing with a corrupt leader. Meanwhile, Nathan Templeton is approached by an ambitious congressman who served with Mac's Vice Presidential candidate, Warren Keaton, and is eager to divulge potentially damaging info in an effort to derail his nomination. Mac's teenage twins resume public school, only this time it's complete with secret service detail and press spectacle, and while popular Horace welcomes the attention, shy Rebecca finds it overwhelming.

When a tell-all book is published about Mackenzie Allen that contains confidential information suspicions arise. Meanwhile, the confirmation hearings for Vice Presidential nominee Warren Keaton begin, but raise questions about his past.

While Mac is busy working on her first State of the Union address, Rod becomes a tad tipsy and is found in compromising position with an intern for all the world to see. Meanwhile, Templeton sets out to find a way to sabotage Mac's Homeless Initiative Bill. Plus, Dickie and Jayne, who has gone back to being Templeton's chief-of-staff, go out on a dinner date.

Mac suffers a burst appendix while aboard Air Force One. Since there is no Vice President in place, Templeton becomes acting President since he is the Speaker of the House and next in line. Meanwhile, there is an air strike that is crippling travel on Memorial Day weekend and Templeton ends up overstepping his bounds and handles the situation the way he wants to.

After a critic of the Equal Rights Amendment passes away and his wife takes over his seat, Mac believes she can amend the Constitution and pass the ERA once and for all. Meanwhile Templeton turns a Get Out the Vote campaign meeting into a presidential debate, Rod is asked to write a story about his relationship with Mac, and Rebecca finally learns the identity of her IM buddy, and both are shocked at just who the other person is.