Measles Outbreak Caused by What?

The politically correct explanation for the measles outbreak is to blame parents who are refusing vaccinations. But isn't it interesting that hardly a word is being said about the illegal alien invasion. The fact that the outbreak started in California makes at least a strong circumstantial case for the likelihood that the "epidemic" is directly linked to Obama's policies of open borders and distribution of potentially sick illegals, especially children, to most states in the nation. (See here.) While the Post article pooh-poohs the idea that illegals are a cause of increased rates of disease, it points out that border security agents are contracting diseases and parasites like chicken pox, scabies, lice, etc. Now if they are getting those is it really unlikely that measles is a problem as well? Most of those officers are probably required to have up-to-date measles vaccinations. Chicken pox isn't mandatory. So how many cases of measles are connected to illegals? Is anyone even looking at it? Disease outbreaks are complicated, but it seems to me that liberals go out of their way to disavow any connection between the massive invasion of medically unscreened illegals and the rise in diseases which have been relatively rare in the U.S.  Political correctness is dangerous when it refuses to consider a common sense question and call for serious study. I agree with Ben Carson who certainly has the credentials to question the politically correct meme.