As a I discovered a couple of years ago by reading the Congressional debates over the 14th Amendment, one should never rely on anything John C. Eastman says about the history of birthright citizenship bloomberg.com/opinion/articl…
This is from Andrew Johnson's justification of his (subsequently overridden) veto of the 1866 civil rights act, which was the precursor of the 14th Amendment 
Here's Jacob Howard of Michigan, author of the 14th Amendment, explaining birthright citizenship in Senate debate on May 30, 1866 memory.loc.gov/cgi-bin/ampage…
That phrasing is a little confusing, but it's quite clear from surrounding context that Howard meant to exclude only foreigners who belong to diplomatic families
For example, here's what Howard ally John Conness of California described as his understanding of the amendment (with which Howard made clear that he agreed) memory.loc.gov/cgi-bin/ampage…
After the 1860s attitudes on such matters in Congress and elsewhere changed quickly, and the Supreme Court tried a few times in the late 1800s to narrow the meaning of birthright citizenship. But the authors of the 14th Amendment clearly understood it quite expansively.
And realize that trying to divine the intentions of the authors of the Constitution is (deservedly) out of fashion, in this case the text also is quite clear.
One clarification: Jacob Howard was *an* author of the 14th Amendment, but *the* author of the birthright citizenship language. He was a lawyer from Detroit (born in Vermont, educated at Williams). en.wikipedia.org/wiki/Jacob_M._…
Lots of perfectly nice countries don't have birthright citizenship, and I'm sure there are valid arguments against it. But it's the way things have worked in the U.S. since its founding, and was written into the Constitution in 1868.
And if you'd prefer to read all these same arguments being made by a conservative lawyer whom Trump appointed to the 5th Circuit U.S. Court of Appeals in 2017, here you go gibsondunn.com/wp-content/upl…
Finally, I did a little reading about Jacob Howard, the author of the birthright clause, which led to this thread:
