This 'Three Strikes' rule is a real problem in America, removing a judge's ability to exercise discretion and well...judge. Also, the jury may not be informed about it before deliberating.
I sat on a jury once for a car thief. He totally did it, the police detective who testified was very thorough and professional, plus the accused did not dispute that he'd been caught driving the stolen car (he blamed someone else for the actual theft) but we listened to both sides and deliberated for a couple hours, considering everything. There was a lot of solid evidence, I am certain he did it even though I'm sceptical about what the police say (I have absolutely seen them lie under oath on multiple occasions). I am well aware of the concept of jury nullification.
We were a little confused why the guy didn't take a plea deal and went to trial but we took the job of jury seriously and after looking at the evidence we were comfortable saying he was guilty. The problem was that we had no idea this was the guy's 'third strike' and the judge mentioned this only a moment before sentencing him to life imprisonment. Several on the jury were clearly surprised by this and I think had we known it may have changed our verdict.
The defendant was a young man, and I am not convinced that sending him to prison for several decades for stealing a car (which was recovered undamaged) is of any benefit to society. Being on a jury means you are definitely not going to see the 'big picture' and when combined with mandatory minimum sentencing, this can be a problem.