Diet Coke has almost become a secondary character in Impeachment: American Crime Story because of how heavily it’s been featured, which amounts to a commentary on the era’s culture rather than an ad. TV shows are notable for making spectacles out of certain products that reoccur in the series when paid for the advertising. One of the most notable recent examples is Coke’s own vast, obvious presentations in Stranger Things season 3. American Crime Story season 3's true story features a strange amount of Coke as well, but it’s not for the typical product placement reasons.
From the first few moments in Impeachment episode 1, nearly any drink in a character’s hand is a Diet Coke. Diet Coke has a strange presence in Impeachment, whether it be the drink in Vince Foster’s last meal, Linda’s beverage with a Weight Watchers meal, or a code for Bill Clinton and Monica to go to the back office alone. American Crime Story’s season is commenting on toxic cultures of the mid-‘90s, and Diet Coke was a staple of this era, with the 1995 Diet Coke Break ads even coinciding with the real start to the series in 1994. While the soda is also used to bring viewers back to the ‘90s, its primary purpose is for the characterization of its core players.
It’s not a coincidence that Impeachment’s Monica Lewinsky and Linda Tripp are the characters most commonly seen drinking Diet Coke. The soda was lauded as the “health drink” of the ‘90s, joining a fad of toxic diet culture that clearly affected the women of American Crime Story. Monica and Linda, both of whom are mocked and belittled by the media for their weight, bond early on over their shared loyalty to Weight Watcher meals and Diet Coke in their pursuit to lose weight. The presence of Diet Coke in Impeachment is an example of just another toxic expectation placed on women and how details of a woman’s body were placed under scrutiny by the media and society at large.
Diet Coke’s role in Impeachment also connects to the real-life trends followed by President Bill Clinton. Before Donald Trump became notable for the “Diet Coke button” in his office, Clinton was an avid fan of the drink, even burying an empty can in a time capsule at his eponymous Little Rock library (via The New Yorker). With the drink's popularity waning over the years, it remains an artifact of the Clinton generation partly due to his role in inadvertently marketing Diet Coke as associated with power.
According to Impeachment, Diet Coke also played an important role in covering up the relationship between Bill Clinton and Monica Lewinsky. By a few episodes in, viewers are let in on the inner knowledge that going to the “Diet Coke room” in the Oval Office is their euphemism for getting intimate. It’s unclear whether the Coca-Cola Company gave showrunner Ryan Murphy a paycheck for all of the Diet Coke references, but considering it’s being associated with the toxic cultures of the ‘90s, it seems unlikely. Outside of the president’s rendezvous in the Oval Office, Diet Coke is hardly even verbally mentioned in Impeachment: American Crime Story. Instead, the “health” beverage serves as a period piece decoration in any applicable scene.