I think the individual mandate would cause an immense amount of economic hardship to the majority of Americans especially if implemented during an economic downturn such that we have been mired in for the past several years. When implemented in conjunction with an obvious socialist power grab, it was double plus dangerous. This is why I was against the current mandate. 20 year old opinions on the subject are largely irrelevant imho.
I'd love to see some evidence Santorum was opposing the individual mandate back in the 1990s when the Heritage Foundation first proposed the idea.