Please allow me to develop another view. In the Declaration of Independence, the Founders made this declaration:
We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness.--That to secure these rights, Governments are instituted among Men, deriving their just powers from the consent of the governed
Our Founders outlined the purpose of our government, to secure our rights, and where our government derives it's legitimacy, Our Consent, and what type of power that government would wield, Just Power.
Now our Framers carried this same thought forward a dozen years later in the preamble:
"We the People of the United States, in Order to form a more perfect Union, establish Justice, insure domestic Tranquility, provide for the common defense, promote the general Welfare, and secure the Blessings of Liberty to ourselves and our Posterity
So, forming a more perfect union is not a one shot deal and more completely securing the Blessings of Liberty is not a task that ended with the Framers, rather, it's a job that continues to this day. The Blessings of Liberty are more perfectly secured today for minorities, women, and those of fighting age are more perfectly secured than they were at the time of our framing.
We happily sit in judgement of every shortcoming of those that came before us, but, are there fundamental rights today that we could more perfectly secure? Anyone who has spent much time in an inner city would have to be Stevie Wonder not see some opportunities.