I'm not the person you asked and as an Australian it's difficult for me to find a concrete irrefutable example of the USofA IRS being weilded as a political weapon on short notice.
I can, however, provide two examples of an incredibly
unlikely event that happened to two political enemies of the then seated POTUS:
https://www.nytimes.com/2022/07/06/us/politics/comey-mccabe-...
As outlined the Comey | McCabe audits appear to have all the likelihood of jeering at the president and then being struck by lightning.
This does appear to be something specific to a particular POTUS and not a general practice.