This was an interesting article. However, one thing that wasn't discussed is the correlation between existing population density and resistance to new construc

This was an interesting article. However, one thing that wasn't discussed is the correlation between existing population density and resistance to new construction. San Francisco is notoriously opposed to new construction, but it does have relatively high population density by US standards. I'm not saying that this means the opposition to new construction is justified, but I do think we might want to investigate the possibility that population density may play a bigger role than political liberalism. This could be a difficult one to tease out, mainly because there aren't all that many highly dense areas that lean heavily conservative in the the US. New York, Boston, San Francisco, Washington, Seattle… they're pretty much all liberal cities (as measured by percentage voting for Obama vs Romney).