In my (former) line of work, it wasn't enough just to be a citizen. One had to be eligible to hold at least a Secret clearance.
This article seems to me to be a lot of ado about nothing. Or, more likely, it's a leftist attempt to hit all of the leftist emotional buttons that get them into frothing rage against anything pro-America.
How do you do a really complete background check on someone from another country?
Depending on the country, some don’t even have birth certificates...they are born at home in a hut village.