Earlier quoted context omitted.
It is, but as with many founding principles of the US, they don't always live up to them. I mean, Thomas Jefferson said it was self-evident that every man was created equal and had the right to life, liberty and the pursuit of happiness, yet he kept people as property in slavery. That just about sums up American theory vs practice. Same with the legal system: plenty of innocent people have been executed despite it be…
To be fair to Jefferson, he supported the eventual emancipation of slaves and the end of slavery, was strongly opposed to the international slave trade (he banned it) and freed some slaves. His stated reason for not doing more sooner was that he thought it would bring about immense unrest. And of course it did, in the end. The bloodiest war in American history.
What a ridiculous reason in hindsight, huh? "Yes, the inevitable reconciliation of our gross injustices against fellow man will be fixed one day. But not now, because I like the comfort of the status quo and would prefer white people not die for a principled cause."
To say nothing of his own slaves, this fickleness of leadership is not what American politics should aspire to.