I think Ted Cruz bears true allegiance to himself above all else. He may have pulled the wool over your eyes but I see through his illusion. He's a manipulating lawyer that knows he isn't eligible to be POTUS and has determined to subvert the constitution in order to get what is best for him.
Allegiance to America is the root argument and intent of the founders being made here...
He's not eligible according to the constitution. that's the root argument. Get a constitutional amendment if you don't like it.
So your point is a foreign born POTUS (Cruz, who left Canada when he was four) or a POTUS of two non-citizens (Rubio, born on american soil) would have dubious allegiance to America...?
Loyalty to the country is nice but it's the constitution that we must bear and swear primary allegiance to for without our constitution we have no country. Ted Cruz does not bear allegiance to the constitution by subverting it. He is, therefore, a threat to the constitution and; thereby, to the country. hence, his allegiance to this country is, as you suggested, dubious.
"I, _____, do solemnly swear (or affirm) that I will support and defend the Constitution of the United States against all enemies, foreign and domestic; that I will bear true faith and allegiance to the same; and that I will obey the orders of the President of the United States and the orders of the officers appointed ...
The oath of enlistment.
And if you think I don't take that oath very seriously, you are mistaken.
Oath of office (Senate)
I do solemnly swear (or affirm) that I will support and defend the Constitution of the United States against all enemies, foreign and domestic; that I will bear true faith and allegiance to the same; that I take this obligation freely, without any mental reservation or purpose of evasion; and that I will well and faithfully discharge the duties of the office on which I am about to enter: So help me God.
Should he resign?