I don't know why the left are so bad at elections but it seems Bernie Sanders supporters in the USA have been affected by the same syndrome as Jeremy Corbyn supporters here and that involves letting into power the very people or party that you want to keep out.
Sanders supporters are booing and refusing to vote for Democratic nominee Hillary Clinton which means less votes against the Republican Nominee Donald Trump and in turn could see him sneak into power.
Over here, Jeremy Corbyn cannot win the next election but the Labour Party members are refusing to overthrow him for someone who can and the anti-Corbynites are refusing to vote and so the Conservative Party slip in for another five years.
Supporters of Sanders and Corbyn seem unwilling to face the reality that their guys cannot win power and so seem willing to let the 'enemy' win rather than contemplate voting for someone else of the same side.
Cutting off your nose to spite your face is never a good tactic, and especially not with as something as important as who runs your country, but they need to make the shift from who they want to win to making sure they stop who they don't want to win.
You may need to hold your nose as you vote for Hillary or whoever finally replaces Jeremy but it is always better to have someone from your side of the fence in power who shares some of your beliefs and values rather than someone from the other side who is your polar opposite.
Hopefully Sanders and Corbyn supporters will wise up to this fact because five years is a long time to spend moaning about the 'enemy' getting in and a long time to wait until you get the chance to kick them out again.