IMHO - the secret service does a pretty good job. IMHO - they are much more professional than the FBI. Just cause they get caught banging hookers in a foreign country and have some issues with alcohol and dead presidents - doesn’t mean they don’t know what they are doing.
Much of what is done is clouded in urban legends and blown out of proportion.
Here’s an interesting case involving the perhaps less known half of their duties - stopping counterfeiting:
Even when dealing with “supernotes” - you again have stuff that is mysterious and perhaps a bit of propaganda thrown in. Various countries have been blamed for these at various times and the Swiss government apparently has raised eyebrows at some of the allegations made by the US on some of the matters.
Other than the FBIs record on stopping kidnap pings - there are very few other serious crimes that are caught as well as the Secret Service does with counterfeiting US currency.
The fact that that being US president is one of the most lethal jobs in the world, but isn’t perceived as such - I’m not sure what to attribute that to.
In the last 52 years they’ve had a pretty good track record. Sure Reagan got shot, and I’m sure there are things that could have been done different, but they seemed to do pretty much exactly what they were supposed to when the shots were fired likely saving his life (although perhaps accidentally getting things worse by the nature of the protection).
The fact that they can keep him safe even when overseas (one close miss in Georgia if memory serves) is also pretty amazing.
They are pretty much the only agency I know of that investigates EVERY crime that falls under their jurisdiction (well the threatening the president and counterfeiting thing). Not sure about the electronic crimes stuff they also deal with.
I found the book:
Confessions of an Ex-Secret Service Agent
To be highly informative and entertaining. Included are anecdotes about investigating someone for counterfeiting a few quarters and the time Nixon (as ex president) wanted to go to the post office himself and mailed himself a package and the clerk (who was told by her boss “no, he doesn’t have to pay postage” (franking privilege) and the clerk asked why not and the supervisor said “cause he used to be president of the United States” and the clerk said “I don’t care who he was - the scale says $5.22”)
FWIW - Nixon wasn’t trying to get out of paying the $5 (or whatever it was) - the supervisor was the one who noted this.