President George W. Bush (1/26/06):

I like the competition of ideas.

NASA climate scientist James E. Hansen (1/29/06):

The top climate scientist at NASA says the Bush administration has tried to stop him from speaking out since he gave a lecture last month calling for prompt reductions in emissions of greenhouse gases linked to global warming.
[...]
“They feel their job is to be this censor of information going out to the public.”