I have lived all my life near the Canadian border. I have known many people who have dual citizenship usually because one parent was Canadian and one parent was from the United States. I also come from a military family. When a child is born abroad outside of a US military installation the parents have to file paperwork to let the US government know about it. Regardless of the child's actual citizenship status, if the parents don't do this it can and will cause a lot of headaches later.
Most of my friends and acquaintances have preferred to maintain their dual citizenship as Ted Cruz did up until he decided to run for President. This has perceived and actual benefits. I am not a lawyer; I do not know how this would play out in a real court.
When I was in high school we were taught that the founders specified one office in the land that required one to be a “natural born citizen” and that was the presidency. I was taught that this was because the founders did not want a president with “divided loyalties”.
So regardless of what the definition of natural born citizen is eventually decided to be... by definition someone who has dual citizenship has “divided loyalties”. Since Ted has now renounced his Canadian citizenship maybe this isn't an issue anymore.
Senator Cruz should not expect to get the hands off treatment that Obama got on the questions about his citizenship from the media. This issue needs to put to rest soon and Senator Cruz is the one who needs to be pushing hard to get this behind him... and I don't mean by subterfuge and attacking other candidates
My children were born on a Military Installation - US Army Hospital Berlin and I still had to get a FS-240 so I could get a Passport for them, don’t remember what I needed for my Army benefits. As far as the dual citizenship I never gave it much thought, I know my children never thought about it, which Cruz also did, until he realized it might become an issue.
Fair or not, the issue of divided loyalties is viewed prospectively, based only on the circumstance of birth. We don’t know how any individual will turn out, 18, 30, 50 years later. The test is at birth, until we open the office to naturalized citizens, then it becomes whatever/whenever.