Our small town of 21,172 has a SWAT team. I think in part it has to do with the unions, SWAT trained officers can make should make more money so train them. There is also the thought that if the jurisdiction has a SWAT team they should use them, so they do.
Excellent article in a long line of excellent articles by author concerning police militarization and the War on Drugs.
The common denominator in the examples cited by Radley Balko is that there were NO CONSEQUENCES for their actions to the police officers involved. None. They were not punished, suspended, charged. Nothing.
In summary, the War on Drugs is a War on Americans.