Despite how obvious it is that the perpetually recurring "arguments" given against gun control are bad, many people in the United States are taken in by them. So why aren't these bad arguments more easily dismissed?

Suppose that the Center for Disease Control (CDC) funded research which found that individuals who eat meat are more likely to die of heart disease than those who don’t.  (I am making this up; I have no idea whether this is true or not.)  The meat lobby objects and says that the CDC should not be allowed to fund research that advocates against eating meat.