Sheer baloney. Simple economics says you only displace the research into other hands or drive it underground. Which option do you prefer?
I don't see what the problem is with taxpayers deciding how the government spends their money. Do you? Sure others will do the research, but presumably with less money, without Uncle Sam writing checks. The underground comment is silly. Even assuming the issue were one of funding rather than prohibition, the idea the research would be done illegally in some basement is ludicrous. It would just be done in countries where it is legal.