There is an article on CNN today about Hillary's statements about being a grandchild of immigrants not matching the facts. The article also says that 7 of her great grandparents were not born in the US. I tried to use WikiTree to fact check the article, but we don't have a lot of information about where her grandparents and great grandparents were born.
The article is at:
http://www.cnn.com/2015/04/16/politics/hillary-clinton-2016-grandparents/index.html
Robyn, have you seen this article by Megan Smolenyak that says a lot of online trees have errors about one of Hillary's grandmothers? (In a nutshell, two women named Hannah Jones were born in Scranton, Pennsylvania around the same time, and so many people choose the incorrect Hannah Jones.)
Robin, are you aware of this site about her ancestors? Obviously it may not be correct but at least they have listed all sources which is a good start. Having Rodham/Roddam ancestors from Duram and Northumberland myself I'd be interested the outcome of your findings.