Nor should it be in our republic. There is no national security override to our rights in the Constitution.
So there's that.
Or was there an implied /s there?
There's a widespread conception that candidates are picked via meetings in smoke filled back rooms - that used to be true, but it isn't true (certainly not in the same way) anymore. Read up on the stories of various "insurgent" candidates in both parties over the last 20 years - the common element is organizing and campaigning so that primary voters actually check the box for you.