Character mistake: Will's tax demonstration to his volunteer staffers is incorrect. He applies the various tax rates to the entirety of each salary range. The person who makes $150K and is in the 36% rate...in his example he has them paying 36% on their entire salary, not just the portion of it that puts them ahead of the next lower tax rate. If the tax rate jumped to 70% at income of $1M, and a person earned $1,050,000, they wouldn't be paying the 70% rate on all $1,050,000 of their income, only the last $50,000 of it. Will's example makes it look like they would be.
College Kids - S4-E3
Character mistake: At the Rock the Vote rally at the Cambridge MA House of Blues, CJ Craig claims that 18-24 year olds are 33% of the population but only 7% of the votes. This is false: per the 2000 Census, which tracks population based on 5-year age cohorts, all persons 15-24 totals only 14% of the population. From that we could estimate the 18-24 population in 2000 as no more than 10%. See http://www.census.gov/population/www/cen2000/briefs/phc-t9/tables/tab01.pdf It is possible they meant all persons 24 and under, who make up approximately 35% of the population.
Chosen answer: A really annoying innate lack of sense. My friends and family say the same thing all the time, and I'm endlessly trying to correct them. I think people just don't know any better and (ironically) couldn't care less that they're speaking incorrectly.