The economy is working against the low and middle income families. As you pointed out the drop in Home Values which is the most significant asset most middle class people have is a real problem. The high energy prices are worse then a tax increase because it impacts ALL economic groups including the low income families. The high personal debt is another issue that holds very real problems for many people in the future. Continued loss of manufacturing and high Tec jobs and the formation of lower paying service jobs without benefits are harming the average workers. From almost every angle the low and especially the middle income families are in real trouble.
So who is the cause of these problems? Let's take your argument apart:
1) Drop in home values. Consumers who couldn't manage their own money took advantage of generous credit terms and began buying homes they couldn't afford using adjustable rate mortgates. As ARMs tend to do, they eventually went up. As interest rates have gone up, the housing bubble began to burst which was long predicted (just like the Internet bubble did before it). The middle class, not the lower or the upper but the middle class are the ones who drove this.
2) Our energy prices go through the roof. As the middle class (i.e. majority of individual consumers) kept buying products that consumed a lot of energy and stopped caring if they purchased products that were manufactured in countries that are extremely energy inefficient (especially in China) the supply of energy could not keep up with demand resultin in higher energy prices. (the main reain our energy prices are going up and will continue to go up -- we're only at the beginning of this pain -- is China's rapid industralization).
3) We continue to lose jobs overseas because of three primary reasons 1) Our manufacturing labor is too expensive and uncompetitive. 2) We are not producing enough high tech talent domestically for large corporations to be able to staff their technical needs in an affordable way and 3) Because American consumers have no loyalty to American-made products and hence, issues 1 and 2 become absolutely problematic.
So yes, middle class Families are having some challenges (it's a far cry from "real trouble" given the strong economy and low unemployment we have). But they are challenges of our own making.
Americans shop on price. And they often shop on price alone. And that has many unintended consequences.