The flaw in marx's theory of history was that he believed the inequalities of wealth and income of feudalism and capitalism were moral equivalents despite the radical and utter differences in their source and nature.What he ignored was the fact that under capitalism economic inequality rests on differences in productive contribution, which contribution operates to the benefit of all.
Nice textbook definition; too bad it no longer applies. I hope you're not suggesting that $billion dollar no-bid contracts awarded to political favorites are rewards for "productive contributions".
Rather, strike the $billions - how about the $trillions upon $trillions handed over to banks and other favored, connected financial institutions, with not one, single prosecution for fraud?
What Marx understood and articulated, is that the capitalist system eventually corrupts the state to the point where the two are inter-meshed to serve only insiders.
The solution is to be ever vigilant in upholding anti-trust, but of course, that is practically an impossible task. Witness the creation of the Fed over 100 years ago - the situation we find ourselves today with all pervasive crony capitalism was baked into the cake long before any of us were alive.