lol. even donald trump, again. makes for good television i suppose, for those who watch such a thing.
It may not be true that anyone can grow up to be President of the United States, but it does appear to be true that just about anyone can be a candidate in the presidential primaries.
I came across an item in The Hill that lists all of the declared candidates for the 2016 Republican presidential nomination up to about June 20, 2015.
If you have accepted the common perception that the field is very over-crowded, the following list of the declared candidates whom you have truly never heard of may make your head spin. I have omitted all of those candidates with any national name recognition.