We further tested whether these patterns were a misleading byproduct of demographic factors. For example, people who largely get their news from Facebook might be younger and hence less likely to be vaccinated, independent of their news consumption.
This is another overgeneralized claim. Making broad statements like this, cuts the articles credibility. To say that there were further tests and not include the results, experimental information and data analytics. By this point in the article, things start to sound extremely coerced. When thinking of it deeper and doing research, certain press companies are funded and have paid partnerships with political organizations. This makes me want to do a further investigation and test if the Washington Post is financially backed by maybe political Pacs or Biden's administration. The lack of credibility in the article makes readers question these things.