Cruz is an outanding Constitutional scholar who has pled cases before the Supreme Court, however, so it is difficult to imagine your fears coming true, but I can still imagine it happening.
As I stated before, it should've been solved during the first Obama administration. Some sort of process should've been put in place to determine eligibility, before Obama's second run.
Now, because of Trump, Cruz will have to talk about eligibility, and get some sort of process in place for future elections.
I support Trump but wish he would take a pass on any saying anything remotely negative concerning Cruz, Christie or Carson. Keep the focus on Clintons and Obama. Especially Obama, just keep going at him til he cracks in public.