Agreed. I can't believe this is actual practice in the States. I could understand maybe on your third strike you get a small prison sentence - and I mean small - but not life. If it was a serious crime maybe but not for silly little ones like this especially when it looks like entrapment as well.
Life sentence for $20 worth of weed is certainly questionable.
Questionable? He sold some weed. Who the hell would think this is an ok sentence or the right thing to do?
However you'd expect someone who's been convicted 3 times already to have come to terms with the shortcomings of his/her particular lifestyle. I'd imagine that after serving his first sentence, he would've already decided that going back to prison is an acceptable risk when it comes to fulfilling his needs.
Don't do the crime, if you can't do the time. I understand that the guy might have been dealt a particularly shitty hand from the start but that's no excuse for not taking full responsibility for one's actions/choices.
But there shouldn't be any 'time' for selling a small amount of weed especially not a life sentence or anywhere near it. Some people don't have many options to survive and if that's the case then selling small amounts of drugs may be his only recourse.