America's founding documents - Declaration of Independence and US Constitution - were a major step forward in the rights of citizens to govern themselves, as opposed to the subjects of monarchs. England had made advancements with Parliament, and the USA improved on that.
Since then, as you noted, multiple Amendments have broadened those rights to former slaves and women, and civil rights legislation was passed to strike down Jim Crow.
In other words, despite setbacks, steady progress has been made. There is truth in MLK's statement that the arc of the moral universe is long, but it bends towards justice.
The current fascist regime threatens to turn it sharply back the other way. The Party of Lincoln has become an utterly corrupt tool of oligarchs intent destroying rights and replacing our imperfect representative democracy with authoritarian rule.
Most of America's Founders were men of the Enlightenment, but they were men of their time. The man who wrote "all men are created equal" as a defining principle of the new nation owned slaves, as did our first president who set the precedent for the peaceful transfer of power.
Our current president is a creature of ignorance and malignant narcissism who attempted , by conspiracy and violence, to prevent the peaceful transfer of power. Now he has every intent to prevent free and fair elections to keep and expand power for himself and despots to follow.
The long arc of righting wrongs and extending the power of the vote to more people is facing an existential crisis that must not be ignored.
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