Fears have been expressed that plans to increase CO2 emissions restrictions in US states will lead to little change in national emissions since stringent states will simply import cheaper energy (and goods) from less stringent states (see link below). Having done a lot of work on the pollution haven hypothesis I would be wary of making this claim too forcefully. Evidence has tended to be very mixed, although several studies have suggested that inward FDI into the US does tend to go to states with lower regulations, other things being equal.
The news article below also mentions in passing that the US is currently planning to construct up to 120 new coal fired power stations. In light of yesterday's protests outside a coal-fired power station in the UK, these plans seem remarkable (see 'Power Station Protests' below). Once again we see little evidence of climate change being taken seriously by the US government.
U.S. State CO2 Laws Won't Prevent Coal Boom