The Democracy thing is a state and local thang. Capitalism is national.
She could have said - capitalism triumphed over the Republic.
Our national government is also a representative democracy, it's not actually wrong to use the word in describing our form of government at the state or national level as a generality, unless you further qualify it by saying 'Popular democracy' or 'Athenian democracy.'
'Capitalism' is not a form of government at all, it is an economic philosophy or system that can exist under any form of government that allows for the private ownership of the means of production and the freedom to hire employees and sell the products. An absolute monarchy like Saudi Arabia can be Capitalist, while a democratically-elected government can be so Socialist in its economic organization that large enterprises cannot be brought into existence without state ownership coming into play (They generally aren't, because actual control of them tends to fall into the hands of oligarchies who have a vested financial interest in private ownership of property for large enterprises).
Now this is just my personal opinion, but the endless hairsplitting and one-upmanship about the use of the word 'Democracy' to describe the US by anyone with whom we disagree does not make us look smarter or win arguments, it just makes us look like nit-picking twerps, since our stickling about it is not entirely correct either.
