I think it's generally wise to take a grain of salt with anything that seems to prove a partisan point. Whether that's justified in this particular case, I can't say.
this type of extraction of trends from unrelated data is basically the hardest all types of research to do well. It's also, maybe more than any other type of research, easily influenced by confirmation bias. I think we all want to see the connections in data (or lack thereof) that we want to see, and that's evidenced alone by my own hesitancy to accept this conclusion.
See also - Spurious Correlations
, which is a fun little website.