Why would you want to reduce the importance of the member state?  Government that is close to the people has the most legitimacy.  I would imagine that Spaniards would rather have their laws come from Spaniards who live in the region than bureaucrats from some other country living in Brussels. Those that dont, probably just dont like how the system runs in Spain, do not have the political ability to change it there and probably want their compatriots in the EU to impose it.

In the US, the states have direct control over their own regions. The federal goverment, while supreme, looks over the nation.  

Terry