I've been thinking about a response, and in doing reading I'm not as confident in my own premise anymore. Yes I'm talking about the middle class in the U.S. and I agree that globalization is increasing the middle class worldwide.

If we accept the American middle class doesn't have it tougher today, we still have to answer why the issue of "job creation" was such a hot-button issue in the 2012 election. Obviously the 2008 market crash has a lot to do with this as unemployment rates increased significantly. I still think that times are tougher now generally for the middle class than they were in the post-WWII "golden age", where secure jobs were much easier to come by with little education, and unions were stronger and fought (often successfully) for higher wages and greater benefits for largely unskilled labor. I think this set up expectations for a generation that were passed down to the next. This doesn't mean that the middle class is doomed of course, but it does suggest a more competitive world that perhaps can be written off by "the golden age couldn't last forever".

Now, the American economy is transitioning more into the Tertiary sector, and away from manufacturing. This isn't bad news for the middle class per se, but it does mean that they have to be more educated than ever to keep up, and I think a lot of (mostly older) people are falling behind because they've been riding the wave of the golden age that's been over for a while now. I suppose that's an inevitability of a transitioning economy and perhaps accounts for some of the feelings of discontent that seem to exist in the public.

Here's an article that covers some of the symptoms of the increased difficulties of today's middle class. It contradicts your assertion that purchasing power has increased.

Still, that was no match for the 56 percent jump in the cost of housing, the 155 percent leap in out-of-pocket spending on health care and the double-digit increase in the cost of college.

I'm sure that purchasing power has increased for some things, but the costs mentioned above aren't trivial, and the increased cost of college is especially worrisome given the increased dependence on higher education.