It seems to me you can't begin to answer the question of which class rules until you have settled on a) what defines a "class" and b) what constitutes "rule". The problem is that these issues have troubled and divided Marxists from the beginning and have never been resolved, though much blood has been shed over the differences.
For example, which class ruled in the former Soviet Union (and China): the working class? a higher form of (state) capitalist class? a new (bureaucratic) class? the peasantry? Does a class have to be directly and predominantly represented in government in order to rule: Were the capitalists no longer the ruling class in the fascist countries in the 30s? Do they still constitute the ruling class where labour and social democratic parties originating in the organized working class form the government? My own view: A. Class is determined in relation to how individuals maintain their "material conditions of existence" - pay and social benefits for wage-and salary-earners; profits and dividends for the stock- and bond-holding bourgeosie; and, at one time, rents and other forms of tribute in the case of the landed aristocracy. B. It matters less whether your class of people hold power directly than that the government advances its interests as against that class or classes of people who rely on other assets and forms of income to maintain their living standards. This seems to me to be true in the broad sense, although like all generalizations, it does not account for nuances and exceptions. There then arises the question of whether classes "in" themselves are classes "for" themselves. The minority classes based on landed and industrial property have historically shown a great deal more class consciousness and cohesion than the mass of small propertyholders and wage-earners. But all classes have been divided vertically by income and status, and horizontally by nation, race, religion, gender, etc. These factors have all served to erode class consciousness, often to the point where it class as an objective category no longer appears to exist, and seems especially to be the case in periods like the present when when the social system is stable and expanding.
