voters 是不可数名词？

However much United States voters may agree that there is waste in government and that the government as a whole spends beyond its means, it is difficult to find broad support for a movement toward a minimal state.

这个句子是对的，为啥用much呢，我一开始就把这个选项给排除了

多谢各位：）

agree with AlienX, and I give some supplement...

much
            may provide a strong mood effect, and however much can't exchange with however..(BY语法全解)
and no matter how equals to however, but not matter how cannot be used in object clause and subject clause, and sometime it did't as concise as however (a method used when you cannot choice between the last two options)...