Alexander és Reed mellett csak a testőr, Duane Stevendson ([[Ving Rhames]]), és az orvosi személyzet, aki Mitchell elnök ápolását látja el a Fehér Ház alagsorában, tudja az igazságot. Sem Mitchell szeretőjét, Randit, sem a First Lady-t, Ellen Mithcellt ([[Sigourney Weaver]]) nem avatják be a cserébe.
Alexander rövid távú terve az, hogy Dave irányításával ő gyakorolja az elnöki hatalmat, mint meghatalmazott. hosszú távon pedig törvénytelen tettei miatt Nance alelnök eltávolítása után ő maga venné át az alelnöki posztot, végül pedig az elnöki széket. Mivel a jelentéseket Nance tudtán kívül meghamisították, terve egyszerűnek tűnik. Azonban Dave fokozatosan a saját útját kezdi járni, amivel újjáéleszti Mitchell népszerűségét és zavarbaejti a washingtoni médiát (számos ismert személyiség jelenik itt meg saját szerepében) és a First Lady-t is, aki a nagyközönség előtt támogatja férjét, ám ez csak álcája kettejük rossz kapcsolatának a magánéletben.
Alexander's true agenda is to exercise the power of the presidency through Dave as a proxy in the short-term, while in the long term framing Vice President Nance for illegal activities, allowing Alexander to succeed Nance as Vice President, and ultimately become President himself. Since the administration, with the exception of Nance, was largely crooked, this appears to be a simple matter of shifting paperwork. However, Dave gradually sets his own course of action, which revives Mitchell's popularity with the public and mystifies both the Washington media (several well-known personalities make cameo appearances as themselves) and the First Lady, whose public support of her husband has been a cover for bitter marital strife in their private life. She soon discovers the ruse, and he convinces Duane to take her to see the real President Mitchell, who is not expected to live. Ellen has a minor breakdown and decides to leave the White House. Dave offers to help her leave and the two 'escape' the White House in a borrowed car. During a conversation about what Dave would do if given a further chance, Ellen realizes that he is sincere in his desire to help others, and is not out for only himself. She agrees to return to the White House and help keep up the ruse. On the way back to the residence, Dave runs a stop sign and the two are stopped by police. Unable to sneak back in to the White House grounds, the two boldly enter via the main gate, shocking the guards on duty.
Dave realizes that he now has more allies than he expected, and manages to turn the tables on Alexander by recruiting Reed, Ellen Mitchell, and his old friend Murray Blum (Charles Grodin). Blum, a CPA, helps Dave reorganize the national budget in order to save a $650 million program for helping the homeless—a project the First Lady supported but Alexander wanted vetoed. In doing so, he demonstrates dramatically in a cabinet meeting that he is a much better actor than anyone gave him credit for. Not only does he shut down Alexander's objections (effectively humiliating him), he sways the cabinet and surrounding press into cheering for the new cuts to save the program. When Alexander realizes that Dave is no longer his puppet, he threatens to expose him, but Reed stands up to him and points out that Alexander has more to lose from revealing the fraud. Dave then holds a news conference announcing that he is firing Alexander, and proposing a comprehensive full-employment program to Congress.