The story is based on the Ohio Democratic primary about to take place but a scene notes that one of the candidates has already won the California primary. California always votes after Ohio.
At the end, where Morris tells Stephen there are no phone records, he is mistaken. They can easily track mobile phone calls from Molly's phone to his, and vice-versa.
When Stephen and Ida are talking in the bar, the ice in their drinks is at the bottom of the glasses so it must be glass trying to play the part of ice, but doing a poor job.
One of the very first scenes of the film, Ryan Gosling's character walks out of an Ohio town hall to the street, where a police cruiser from Miami University is parked front and center.
Ohio is a two license plate state. All the vehicles in Ohio are missing the front license plate.
When Paul is sitting in the barber shop getting a haircut, the barber goes over the same spot on the back of Paul's neck. After 6 times, there are no hair clippings and the hair is no shorter.
When they are watching a bank of TVs, the TV on the far left has a "Local 12" lower third, but the reporter doing the stand-up is holding a Channel 9 Microphone.
George Clooney and his wife are having a conversation in the campaign bus, at night somewhere near Cincinnati. But an exterior shot shows the bus pass a "Lansing" sign with the Michigan state route (diamond) symbol.
Stephen asks for campaign petty cash to pay for the abortion, and then adds some of his personal funds and gives the money to Molly. It makes no sense for someone as savvy as Stephen to use campaign petty cash in this situation. He would have been making six figures and could certainly afford to use only his money. He wouldn't use campaign funds and risk leaving a trail.
With the Ohio primary on the horizon, only two Democratic candidates remain and both are vying for the endorsement of North Carolina Senator Franklin Thompson. In the film, an endorsement from Thompson is dealt with as swinging 356 pledged delegates. However, in 2008, North Carolina carried with it only 134 delegates (115 pledged delegates, 19 superdelegates). Furthermore, in the Democratic nominating process, superdelegates cannot swing delegates. Of the 115 pledged delegates, they are proportionally awarded based on primary results.
At one point in the movie, two characters watch the political commentary show "Hardball" right after waking up in the morning. "Hardball" actually airs twice in the evening, at 5:00PM ET live and 7:00PM ET in rebroadcast. It never airs during the morning.
Ryan Gosling's character mistakenly refers to the two lecterns on the stage as podiums when he asks: "Are we going to put risers under these podiums?" A podium is a platform on which the speaker and lectern stand. A lectern is not a podium.