No doubt the reason for this — and this is lesson two — is voters increasingly are so turned off by the political process that they pay attention only on the eve of the vote. We saw it in the United States in the 2014 midterms, thanks to a barrage of negative ads. I expect to see it again next year.

Lesson three, and this part I did get right, is the absolute necessity of “trust” in voter intentions. In just about every pre-election poll, Conservatives and Labor were locked in a dead heat, yet voters gave Conservative leader David Cameron a large advantage over Ed Miliband, his Labor challenger, on the question of whom they would trust more to run the country.

In the end, trust is a far more accurate predictor of the election outcome than any other metric. Even though Britain votes for local members of Parliament rather than prime minister, a lack of faith and trust in Miliband’s leadership capabilities sunk his party in the end.