I've been to several presidential election conventions in my life; the first in 1968 CA State primary convention in LA, where I lived and are up. I was an 18-year-old Bobby Kennedy [therefore, Dem] election volunteer, and had that credential, which was all that was req'd to enter. The national convention in Chicago that year, following Bobby's assassination, he'd tightened security, and personal ID was required to enter.
I attended the 1980 Repub national convention in Detroit for Reagan. No ID was required. I was there on business and decided to attend the night he was nominated officially.
I attended the Demo national convention in 1996 in Chicago for Bill Clinton. I was there on business and decided to attend. My personal ID was required.
If Demos had the same national security concerns at the border, and that retail outlets apply for cigarette and liquor sales, as Demos apply to their own political conventions, we would not have the serious illegal alien [proper annotation] problem we endure in-country today, reaching its maximum effect during the do-nothing-about-it Biden era.