Tom suggests a national enquiry into one club. This is utter nonsense. You wouldn't get a professional worth their salt to make the claim that "the ones who like the team with the blue shirts are more likely to be biggoted than the ones who like the team with the green shirts." This if, of course, because professionals (anthropologists, behavioural psychologists etc) generally don't come from a place of bias to begin with, like Tom does.
The only such enquiry that would have any solid founding in actual science would focus on a much larger group/sample size to begin with. Before you could establish that one club has a particular problem, you would need to study all clubs. If the enquiry did indeed do that, and it was independent, and it controlled for fanbase size, then they would soon realise that all clubs have these problems in very similar proportions. It only appears that Rangers have a bigger problem because the coverage in the media (the only data Tom and others have to go on) comes from a place of bias. Our indiscretions receive more coverage, more condemnation, and sells more papers due to the wider belief in Scottish society that we are the boogey men; a belief that has been cultivated by Independence supporters as it conveniently takes down their political and ideological opponents.
If they done the study in the manner I propose, then I'd be completely in favour of it. They would not like the results.