I agree, it was statistically insignificant. However, I pointed out the "foot-in-the-door" argument; which was being advocated at that time by some in the south.
It is your inane position that is insignificant. Nobody is singing about those old cottonfields back home in New Mexico, Utah, or Nebraska. The Congress made it legal to take slaves to the territories and nobody went. The Supreme Court said the Constitution prevented Congress from passing any law preventing the taking of slaves into the territories. Nobody went. Total 1860 slave population in the territories -- 44.