On energy related broken promises, he's now back to puckering up and smooching Saudi ass again even after promising to distance themselves after the journalist Khashoggi's murder and dismemberment. He'll break more, it's a political reality.
Agreed, just also agreeing with 30 that Biden/Hillary supporters can't have their cake and eat it too by doing exactly that and acting like Sanders not being able to accomplish everything he promised was a political "gotcha" and a reason not to vote for him. You vote for the person most likely to fight for and accomplish what you want, because there's too much unknown (and strong knowns, like Republican's refusal to do anything good with the power of the Federal government) to predict the future.
In theory I'm fine with the idea of the death penalty. Given certainty of guilt (key) and heinousness of a crime, and while I'm for more rehabilitation and integration back into society we have to accept that there are points where people are too far gone and irredeemable, then I'm OK with killing them off.
In practice, it's a system run by human beings with prejudices and ignorance with incentives to impose harsher punishments to appear "tough on crime", and it overwhelmingly falls on the head of the poor and minorities who rarely have adequate defense. Even when serious doubt and legal malpractice is understood by all parties involved we still kill people we know are likely innocent or at least doubtfully guilty.
Maybe when Skynet goes online and can track everyone on Earth in real time with digitally recording nanobots/satellites, and guilt or innocence is known fully I'd be OK with trusting it to carry out executions (though I wouldn't be surprised if they just save time and launch the nukes). Until then, I can't trust people to make that decision.