Given that a US boots on the ground situation is almost inconceivable, the population of Iran is essentially irrelevant, and I doubt that you would have had much reaction if any other congresscritter would not have known, but since it was Ted Cruz you just couldn’t resist.
And how many of the 535 congrescritters know the population of Iran off the top of their head? I would bet considerably less than one in ten. But of course you waste no opportunity to bash Ted Cruz.