The new constitution has put at rest, forever, all the agitating questions relating to our peculiar institution, African slavery as it exists amongst us – the proper status of the negro in our form of civilization. This was the immediate cause of the late rupture and present revolution. Jefferson in his forecast, had anticipated this, as the “rock upon which the old Union would split.” He was right. What was conjecture with him, is now a realized fact. But whether he fully comprehended the great truth upon which that rock stood and stands, may be doubted. The prevailing ideas entertained by him and most of the leading statesmen at the time of the formation of the old constitution, were that the enslavement of the African was in violation of the laws of nature; that it was wrong in principle, socially, morally, and politically. It was an evil they knew not well how to deal with …. Those ideas, however, were fundamentally wrong. They rested upon the assumption of the equality of races. This was an error.”
You have good genes, you know that, right? You have good genes. A lot of it is about the genes, isn’t it, don’t you believe? The racehorse theory? You think we’re so different. You have good genes in Minnesota. ”
Quote One is from Alexander H. Stephens’ Cornerstone Speech, March 21, 1861 as reproduced in full at Teaching American History
Stephens was called the vice-president of the insurrectionists. Abraham Lincoln never recognized the states that left the US Congress as having left the country. The Civil War was not a war between two countries. It was treated more like a law enforcement action. (Though Lincoln did, occasionally, in speeches, informally refer to it as a war, as he did at Gettysburg.)
Stephens, speaking for the rebellious insurrectionists, was firm in his conviction that the most proximate cause of the break, and the consequent levying of arms against the United States at Ft. Sumter, was to maintain (1) slavery as the basis of the southern economy and (2) the position of slaveowners in society.
Furthermore, he was just as clear that the men then in charge of the slave states thought that Jefferson, and his generation, were wrong. All men were not created equal.
Quote Two is from then-president Donald J. Trump, running for re-election, Bemidji, Minnesota, September 25, 2020.
The racehorse theory is that people breed like racehorses. Some have genes that make them better suited to winning races. So, while all racehorses may be horses, they are not all the same. Successful racehorses are a different breed. According to this theory, they are the winning race. The speech is quoted and the theory explained in The Hill.