I'm always a little confused about different states in America having differing laws rather than one set of laws that governs the whole country and admit to being ignorant over why this happens as it would be a bit like different counties being able to have different laws here in the UK. That said, I appreciate that the US is a vastly larger country with a far greater range of cultural differences and understand Robus's point about people wanting to be governed by local representation (We the people) rather than by a central government many hundreds of miles away. I'm assuming that there also remain significant cultural differences between the old Southern and Northern states as an example?

As individual states are so vast, I guess the passing of some more controversial laws (such as an anti-abortion one) could still impact on a significant minority who did not vote for them. Democratic systems will never be perfect and I have often thought that proportional representation would be fairer for example in the UK but I assume that PR is not adopted in the states either?

Excuse my ignorance but maybe someone could explain to me how some laws govern the whole country whereas others are left to indivdual states to decide and what part the Constitution plays in this. Thanks in advance.