Astonishing. Even Tory apologists should be finding this difficult. But they may not.
I've wrestled with it, being back in the area of my true-blue upbringing, and just down the road from the posh school I attended with a bunch of arseholes (but to be fair to them, they differ from the conservatives in that they grew up). The only explanations I've come round to over the last year or so are that people who vote that way no matter what want "freedom," so the right offer to leave them alone the most (some of these people are those who claim the EU were "telling them what to do" etc) and are the better option - and that's backed up for them by occasional dog whistles on 'common sense' (failed) policies of toughness on crime, death penalty and so on.
Plus they're kind of broken, and if pushed to justify the right's terribleness, then the argument is that all politicians are terrible, and therefore, um, so what? One of the arguments they'll go to most often is that "X isn't perfect". Which is the perfect Tory kind of truth - sounds at a glance like something poignant and meaningful, whereas actually it's true of absolutely everything man-made, and therefore meaningless.