My Mum's area was always red (former mining) and changed to blue in 2010. She said all people see is the Conservative MP, who has an office in the town she lives in. She said she is visible, people can go in and talk to her about whatever they like and even though my Mum doesn't vote for her, she said she is a good MP and understands why people do. She said there has been more investment since the seat became blue, their houses have gone up in value, the schools have improved and that is what is important to people. She said they don't care about what they can't see.
I don't know if that helps. My area is a true blue and my MP is properly crap and I have no idea why people vote the way they do here.