He comes from the middle class.

Her income barely maintained her in the lower middle class.

The typical middle-class American baby comes home from the hospital to sleep in his own bed in his own room.

However, like America, Japan is predominantly a middle-class, middle-income country, and so wives do not employ maids, but attend to everything themselves.

Some of the members of the middle class have fallen into poverty.

That party is always pandering to the middle class.