Yesterday was a watershed moment for the Reform Party. They had what is known as a “crossover” moment – overtaking the Tories in a mainstream poll. Polling from YouGov, published yesterday, saw Reform’s support increase by two points to 19 per cent. The Tories remained unchanged on 18 per cent. Worryingly for Sunak, the polling was conducted after the Conservative Party published its manifesto on Tuesday. The polling shows that the dial has moved in Reform UK’s favour. But not only that, in itself, polling like this can push the dial even further. If Reform is lucky, it could cause a snowball …