As I have repeated said, voters who vote because "They always voted <whatever>" are the first to be fucked when their party wins power. Because whatever their party does, they can rely on that vote.
The people who generally benefit from electing a government are the ones who only vote for a party on certain conditions and who would happily vote "diametrically" if they are promised something better.
People who always vote Tory have been well and truly fucked by the Tories over 14 years.