Thats why I originaly said there are no classes in the US, because the only real classes are legal and OP wasn't talking about the law.
The only classes which exist in the US are the 3 legal classes as stated. There are no social classes since non have more authority than anyother, and there are no economic classes as your income doesn't give you more authority over all other people of lesser incomes. Even when you hold authority over employees thats indivigual and with their consent; you still do not have authority over everyone with smaller incomes than yours.
There are groups and demographics, but no classes. Its all perception, its not real.
I despise that word and its meanings. It says essentially somebody is better than me because of some arbitrary notion made up by some twit trying divide and conquer in the political arena. **** em. I don't play that stupid silly ass game. I don't know why more than a few of my fellow Americans get sucked into it but they do. Power comes from within, from knowledge, from ability, from resource, from people. In this country what a lot of people don't know is that most people get into the upper 10% of income at some point in their lives, and then most of them drift back out. Its an unusual statistic for country that few people here are aware of. We are a very transitional country in terms of economics. That's why its foolish in this country to put oneself into a class because in all likelihood you wont be in it for long anyhow. People here are generally not static and never have been. Why put a static label on yourself, why label yourself at all?
I understand where you are coming from, the term "class" carries a lot of historical and ideological undertones.
Like when I say "class" here in Germany, way too many people have the Marxist use of this term in mind. That confuses more than it helps explaining. However, "class" doesn't necessarily denote legal discrimination, but may very well point at the borders of socio-economic classes that are almost impossible to cross despite a lack of legal discrimination.
For from being an expert on sociology, but from what I gathered, many sociologists today rather use the term "social layer". Because, as you say, classes as defined above (static groups of people in a society with rather strict borders) don't exist anymore to the extent they once did (like in 19th century industrialization, which is the situation Marx was looking at). It's much easier now to cross from one layer into another.
But that doesn't mean that hurdles don't exist anymore between the different layers. And it doesn't mean everybody is "equal". The hurdles that still exist open the door for a lot of justified social criticism beyond ideologies such as Marxism.
An example often cited in Germany is the very high correlation between economic status of parents and education level and then economic status of their children later in life -- although most schools and universities are virtually free. Short: Children of rich parents are much more likely to get the best possible education, which in turn results in them getting the best paid jobs and become rich themselves. It is much more difficult for children of poor parents to economically ascend. It seems that the social layers are somehow reproducing themselves and other factors are more crucial than just effort, virtues and talents for social ascend -- or at least more than we wish they were. That's especially problematic because many immigrants are of a poor background, and their lack of economic ascend creates more problems.
Another example would be South Africa. Although legal discrimination of the black majority was abolished, there are still rather static social layers (or classes?) strongly connected to skin color. Whites still are "running the show" on many fields, despite them being a minority, and blacks have a hard time getting a foot into the doors, because these social layers are most likely reproducing themselves to some extent.
You don't need to be a Marxist to point at such phenomena, and to feel they're normatively not a good thing but deserve to be addressed.
