Unfortunately, they are a loud and obnoxious vote, and there's no way for actual science to be communicated against that background.
No doubt, I have a big problem with these people, but it's important to fix the real problem, and make sure that strategy doesn't prove the deniers right. If you suppress them, they become the persecuted "true skeptics" even though they are no such thing... They use pure, evidence-free rhetoric and manipulation of peoples' fears to cast doubt on science.
I think it's kind of useful for scientists to "take back the doubt" in today's current political climate. In a healthy field that's doing real science, there's more than enough skepticism and competition to keep conspiracies from happening.
Unfortunately, as frustrating as it is, I think part of scientists' jobs IS to convince the public that science works. The results are important too, but suppressing the deniers would just give them more power. Making people see that scientific findings have real weight because scientists are constantly trying to prove themselves and each other WRONG is somewhat important.
I think that a lot of the deniers are smart, thinking people without a good understanding of how science works. They get a steady diet of conflicting reports on scientific topics from the media, and they're paying attention, so they see the conflicts. But they don't appreciate how important the conflicts are to the process.
I notice this on the ham radio websites I hang out on. There are a lot of ham radio operators who think solar physics is a ridiculous pursuit because one group is predicting that the next solar cycle will be incredibly strong and another is predicting, on the basis of a different model, that it will be very weak. These people seem to think that we shouldn't try to predict because our predictions disagree.
They're not dumb. But they are totally missing the point.
The findings are important. But they mean nothing if there's a serious doubt in the process. I think a lot of people couldn't imagine setting themselves up to be publicly wrong like the solar physicists do. Then they try to rationalize the public failures on the basis of more familiar motivations: they're doing it to get attention and funding, to advance their careers. They're bad at their jobs and are wasting taxpayer money. They should just hang it up.
I think a lot of the deniers come out of that kind of thought process.