It's fact. The Tory roll has been happening since 2010, since Cameron entered the scene. Boris just needed to turn up & promise lot's of the usual bullshit to the masses.
I voted Labour after weeks of effort to spread the word of the party so please, give it a break. If you are naive enough to believe Brexit has caused a Tory Majority then you havn't been speaking to people around the country. Brexit was way down the list in many northern areas & in the Midlands with most claiming they just don't trust Corbyn but do trust Boris.
The propaganda paid off, as it usually does.