Emotional Response
I've read some sales and marketing articles about techniques for trying to elicit an emotional response from your audience. The broad idea is that if you can get your audience to bond with you or your idea on an emotional level then this is very strong. The heart is stronger than the head, if you like.
I hadn't taken too much notice but after recent world events it strikes me now that maybe there's something in it. I'm thinking in particular about the "Brexit" referendum and Donald Trump's election campaign. In both cases the winning parties made very strong statements, probably much stronger than their actual beliefs or intentions. This strength of message created an emotional response in people, either one way or another - love or hate - there's no doubt it was divisive. Whilst this approach will undoubtedly lose some supporters the division it creates will harden the resolve of those who do follow. They start to feel like a minority being ridiculed by the opposition and it only makes their belief stronger.
This is also connected with the idea that all press is good press. Trump must have had far more press column inches than Clinton. Maybe as the negative press coverage gets whipped up into a frenzy people start to feel sorry for the "victim"?
To give a slightly lighter example, on TV shows like X Factor, most viewers generally pick their favourite in the early stages and then continue to support them throughout. I don't think there are many viewers who vote for a different contestant each week based on merit. If your favourite gets heavy criticism you're far more likely to vote. These kind of shows will always be won by the one who seems like a nicest person rather than the most talented.
Maybe there is something in this trying to make an emotional connection early on?