In the last three major elections (2015 GE, EU Ref and US election), one of the key reasons that left lost is because they have given up the idea of debating with anyone who disagrees with them. They think that anyone who votes differently to them is sub human scum and deserves no time. Why would that convince anyone to vote for their side? In this day and age, so many of my generation use social media and surround themselves with likeminded people and anyone who dares to disagree with anything they say is shouted down. There is no engaging and trying to find out why the person disagrees with them, they just say they are a stupid racist and scum.
There have been cases in the last three elections of shy tory/trump/leave voters as why would people want to subject themselves to abuse? While i believe that you should be open about what you want to vote for and why you will vote that way, i also understand while several people wont subject themselves to abuse just for daring to be different then others. I have tried to debate with many both on Facebook and twitter and i end up just being accused of being a racist ukip voter. Why would i try and engage with people like that again and listen to what they have to say? They clearly don't care what i think and that is why the left will struggle to win another election for a while. They have this smugness about themselves that they are better people then the right and therefore shouldn't engage which leads to the right voting for the Tories or Donald Trump because the left make no effort to engage sensibly with them.
The left also claim the right are racist and spread hate yet a lot of the time in the protests following both Trump election and Tory election there have been death threats issued to people who dared vote for either. There was a video yesterday of a group of young black men beating up a older white male who voted Trump. They claim voting for Trump would lead to a rise in racist attacks yet there they are performing these racist attacks yet it is justified because they didn't vote for Trump. Yet when you compare the reaction of Tory voters to labour winning the london Mayor election, there were no marches they just accepted it and got on with it. Now, we all have a right to protest and that must be protected but most of these protestors are the reason their side lost. They intimate anyone who disagrees with them and alienates them and then wonder why they lose.
Until most on the left accept others have different view points and try and engage with them instead of calling them scum and racist, they will struggle to win another election for a while both here in the UK and in the US.