In brief: most people, most of the time, pay almost no attention to political news even if it’s all across the newspapers, TV, websites and their social media feeds. Here’s some evidence, taken from 101 Ways To Win An Election:
It’s that low level of penetration for political messages which is why, for example, delivering quite so many leaflets make sense. You need that volume for messages to get through.
For more on how to achieve that winning level of intensity, take a look at the rest of 101 Ways To Win An Election, available both as a paperback and ebook. Both versions are now in an updated and expanded second edition.