For the younger folks: Kerry got some seriously badass medals for his military service in Vietnam. People who had been on the same boat as he did, but at a different time, worked with the Republican party to claim that he hadn’t really done what he did. The press ate this up, and distributed it widely, costing him public support and likely the election.
Remember Kerry was miligned by much of the veteran community because he protested against the war in Vietnam. The swiftboat claims helped to fit into a narrative that his service record was flawed, especially against GWB’s controversial record with losing flight status with the Air National Guard.
Snorting coke and going AWOL from the TANG was way more respectable to these idiots.