The car Mr. McAllister drives throughout most of the movie is a 1990 or older Ford Festiva, blue with black bumpers. In the last scene which the car appears, it is a newer model with "color-matched" (blue) bumpers. In this scene, he remarks that his wife got everything including the house, "but I got the car".
The flashback to Paul taking a fall while skiing shows him starting out in a blue and yellow snow suit, but when he's falling it changes to red and black, then when he comes to a stop it is navy and yellow.
The ballot lists two students running for Secretary and three for Treasurer, but when the candidates are seated at the assembly awaiting the election results, there are three students sitting in each group.
When Paul is at the microphone giving thanks for his "victory", Tracy is seen in the background wearing a jacket with a zipper. In the previous scene and the one right after, she is wearing only a turtleneck.
Tracy's hair after she receives her yearbook. When she gets her yearbook, her hair is curled up at the bottom. But when she is shown outside of school a few moments later, her hair is barely curled at all.
In the first newspaper article at the end of the movie, Tracy's mother is listed as Barbara Flick. In the second article she's listed as Judith R. Flick. Both articles are written by the same person, Trent Pappas.
If you pause on the first article relating the story of Mr. McAllister's involvement in Tracy's losing the election, you can read that Tracy is "the daughter of Barbara Flick". When Tracy's mother is sealing an envelope earlier in the movie, her return address clearly states "Judith Flick".
For Jim to correctly change the election result he would have to replace two of Tracy's votes with a new votes for Paul. That way the vote count would not change. Give the timing he would have done better to pocket the votes rather than throw them away only to be found.
Mr. McAllister insinuates to Tracey that he could cause trouble by publicizing her affair with another teacher because she is only 17 years old. But the age of consent in Nebraska, as in most states, is 16. Although there might be a regulation against a student and a teacher relationship.
In the newspaper article about the election, it says that Paul is the son of Dick and Elaine Metzler. However, when they meet Mr. McAllister at the restaurant, Paul's mother introduces herself as Jo Metzler.
When Tracy is setting up her table in the beginning of the movie, she opens five legs on a four-legged table. However, this is clearly deliberate, a symbol of her over-achievement.
The morning after McAllister is stung on his eye by a bee he goes back to the school to get changed. His eye does not appear to be swollen because the prominent side of his face in the reflection is his left eye, whereas his right eye was stung.
The nickname of the mythical Nebraska high school is the Wolverines. However, when the results of the election are announced at the assembly, the name Monarchs clearly appears on the side of the gym floor. This is the nickname of Papillion-La Vista (Nebraska) High School where many of the scenes were shot.
When the students make their campaign speeches, the American flag is hung incorrectly with the blue field in the upper right corner. The correct way is with the blue field in the upper left corner. This is a frequent error not only in the movies but in real life.
Tracy edits a yearbook photograph to remove Dave Novotny, by sliding across a patch of the rear wall - which magically changes en route so that the pattern of bricks will match.
Right before McAllister gets stung by the bee, while he is calling for Linda, a bug can be seen crawling on the camera. It is on the right side of the camera, where the tree is seen, and while it may appear to be flying or crawling on the tree it is obvious that the bug is clearly on the camera because of its proximity and crawling patterns.
When Walt the principal announces over the speaker that Tammy Metzler is out of the running, the set's light reflection is cast on the window behind him.
In the last scene Jim McAllister is in Washington, DC. He says in the voice-over that, having spent the morning on the National Mall, he was on his way to the Holocaust Museum when the scene occurred. That scene was shot outside the Hay-Adams Hotel, which is north of the Mall, just north of Lafayette Square and the White House, and Jim is clearly walking north on 16th Street. However, the Holocaust Museum is in the opposite direction, about a mile south of the White House and only a few hundred feet south of the Mall.
When Paul and Lisa are in Mr. McAllister's office complaining about a conflict of interest, Lisa says, "She's just doing this to get back at me," and you can see the shadow of the boom mic on the ceiling swing back and forth.
When Tracy enumerates her accomplishments, she states she played Hodel in "Fiddler on the Roof", but is then seen singing the part of Chava. Also, Tracy mispronounces Hodel, which ought to rhyme with "huddle", not "yodel".
Gavrilo Princip's surname is misspelled "Princep" on the blackboard following the eighth period pop quiz.
The newspaper articles near the end contain spelling mistakes such as "deceipt" (ie "deceit" with an extra "p"), and "shoe-in" (which should be "shoo-in" as the expression refers to driving an animal, not footwear).
Tracy, in her voiceover after the election, refers to being in the "top seventh percentile"; percentiles do not work that way.
At the assembly, when Tracy is being heckled during her campaign speech, a teacher/school administrator sitting in the front row (gray hair, red sweater) can be seen giggling and smirking.