What did Henry Clay mean when he said "I owe a paramount allegiance to the whole Union—a subordinate one to my own State" in the compromise of 1850?

The american public did not truly take in the horror of adolf hitler's regime until years after the existence of concentration camps was first reported in american newspapers. partly this was the fault of the media, which did not give prominent placement to news of the holocaust. what other factors do you think contributed to the long delay in understanding the holocaust?