Middle class: pols love, don't understand it: a response

In all recent political advertisements and speeches it has been clear that a major target audience within both parties is the middle class, why is this? An article in today's issue of the Herald Leader tried to tackle this question and I found that it was lacking in any new evidence to support its claims. The article posed the question "if we get our economy growing at a decent clip will all be well for the middle class?"...sadly the answer is apparently no. I would place myself in the category of middle class and not surprisingly so would almost all other Americans, so wouldn't it make sense for both parties to try and swing the middle class vote? I believe it would. The author has some ideas about improving the state of the middle class in the future, including better and more jobs and increasing the level of higher education in the U.S. and I agree to some extent, but will this help the middle class or just make it larger?