This is not about Europe vs the US anymore, the way it was back when we were having a similar argument about Kyoto. Today's world is a lot more multipolar than it was then, but Paris was a truly global agreement in which ALL nations participated, except Syria. And Nicaragua, which threw a fit because it thought the targets should've been binding.

Of course you can debate the numbers, and it's hardly surprising that Obama's targets are too ambitious for a Republican president's taste. And as I said, it may not make all that much difference - the US will still make substantial progress on climate change even if the federal government ignores the topic, thanks to the states and cities. But still, stepping out of the agreement weakens American leadership in the world.