That's possible in the USA also, you just have to do that at the State and Local levels (which are comparable in population and ideological homogeneity with El

That's possible in the USA also, you just have to do that at the State and Local levels (which are comparable in population and ideological homogeneity with El Salvador anyway). The USA isn't a unitary state, so it won't move as quickly as unitary states. It's a federal state that shares sovereignty with its constituent States, and the Federal government is necessarily slower than the State and local governments. This is true of all federations, including Canada, Australia, Switzerland, Argentina, and Mexico.