Albeit compared to a poor imitation of Planes, Trains, and Automobiles, Todd Phillips' follow up to 2009's The Hangover is buffeted by the opposite, yet complimentary acting styles of Robert Downey Jr. and Zack Galifianakis. Downey Jr., with his usual stoic/acerbic delivery, and Galifianakis, with his lovable brute persona, mask, for the most part, the unmitigated truth that this story is almost as implausible as the plots of Old School and School for Scoundrels (you know, the movie that tried to have Jon Heder in a lead role that wasn't Napoleon Dynamite) combined (but at least David Cross and Sarah Silverman were in School for Scoundrels to anchor it). Unquestionably, the movies that Phillips creates are not exactly critiqued for their loyalty to certain facets of reality, but Due Date is, at times, so over the top, you find yourself wondering if Phillips found inspiration in the films of The Three Stooges.
The strangest element about the film is the beginning. When contrasted with the rest of the story, it seems almost totally out of place. With the joint efforts of screenwriters Alan Freedland, Alan R. Cohen, Adam Sztykiel, and Todd Phillips himself (that's a fuck ton of writers if you ask me, but comedies tend to always have a mass amount of testosterone spewing onto the page), Due Date opens on a somewhat serious note in that Downey Jr.'s character, Peter Highman (get it, right?), is presumably rehashing an intense and meaningful dream via pillow talk to his wife about their impending child. When he finishes telling the dream, he rolls over to reveal an earpiece in his ear after completing a voicemail message. From this point forward, the expected tone of a Phillips helmed movie is adopted.
From his first encounter with Ethan Tremblay (née Chase), Peter feels nothing but sheer contempt. Their initial introduction occurs as they lock eyes outside of the airport in Virginia--right after Ethan's brother ripped the door off of the Towncar Peter had been driven in. Launching the series of "happenstance events," Ethan manages to switch suitcases with Peter so that, when he has to go through the security checkpoint, he is questioned by none other than Rza for marijuana possession. This leads to the confiscation of the bag, however, in one of many moments of suspending disbelief, Peter is still allowed on the plane without further delay.
The hijinks Ethan wreaks upon Peter's life only escalates from this point forward, ranging from getting Peter on a no-fly list to losing his wallet to having him wind up apprehended by officials at the Mexican border. Through it all, we are supposed to believe that Peter, like some heightened version of a sympathetic and irrational human being, would stick with Ethan throughout this series of unnecessary travails. While certainly a testament to the lengths a person will go to for family, Peter most definitely has other recourse apart from relying on Ethan to give him a ride back to L.A. to see the birth of his son (who turns out to be a girl--in keeping with the whole "you can't control destiny" concept).
The one source of comfort about Due Date is that there is still the conventional use of Todd Phillips-branded humor to compensate for specific plot points of irritation (Peter punching the son of a southern pot dealer named Heidi, played by Hollywood's favorite pick for hot mess characters, Juliette Lewis; Peter not being able to get the money his wife, played by the somewhat underused--in terms of acting talent--Michelle Monaghan, wired him to Western Union because Ethan's real name is Ethan Chase, not Tremblay; Ethan insisting that his wife cheated on Peter with his best friend Darryl, played by Jamie Foxx in one of his less humorous star turns).