We Need States

Germany, Australia, Brazil, Russia, India, Pakistan, Argentina, Nigeria, Mexico, Ethiopia, Chad, Austria, Belgium, Somalia, Switzerland, Venezuela, Bosnia, Malaysia, the Seychelles, Colombia and, contrary to your post, Iraq, are all federal countries. I'm disappointed in your uncharacteristic display of American exceptionalism. It's reminiscent of the Big Brother contestant who opined that Britain should retain its monarchy on the basis that "we're the only country that has one".In fact, most of the world's largest countries have federal governments, with the most notable exceptions being China and Indonesia. China does, however, have five autonomous regions, plus the Special Adminstrative Regions in Hong Kong and Macau, that have considerable legislative autonomy; and for practical reasons stemming from the sheer size of the country the provincial governors have a lot of power in the real world.

The existence of the Senate and the existence of the States are seperate issues. You could abolish either independently.Whilst the decision on the exact composition of the US Senate was taken to preserve the influence of states; the actual idea of the upper house was taken from the unitary Westminster system, where the upper house protected instead the interests of the aristocracy and church.But senates (or, more generally, upper houses) are still common in unitary systems. They're there as an extra check on tyranny. Deciding on the appropriate method of representation is not a simple matter; and an upper house which uses a different form of representation helps to prevent against a tyranny of the majority.Here in Czech Republic, for example, we have a Senate, though it's nowhere near as powerful as the US Senate. It's more similar in power to the British House of Lords. Unlike the lower house, which is elected on a proportional basis using party lists; the upper house is elected on a single-member constituency system similar to the US House of Representatives; and it's elected at different times for different term-lengths. It produces a very different body to act as a check upon hasty legislation.