You know these words, but how often do you stop to think about them? “We the People of the United States, in Order to form a more perfect Union, establish Justice, insure domestic Tranquility, provide for the common defence, promote the general Welfare, and secure the Blessings of Liberty to ourselves and our Posterity…”

They belong, of course, to the Preamble to the U.S. Constitution. That remarkable document is not just the blueprint for our political system.

Its Preamble is also a profoundly aspirational call to arms. Because when you read it, it’s hard not to ask yourself how we’re doing — at establishing justice, promoting the general welfare, securing the blessings of liberty, and, in sum, creating a more perfect union.

It’s especially hard to avoid asking this question now, when the warnings of democracy in retreat are all around us. Yet it’s also undeniable that we’ve come a long way in this country and in other democracies. We seem to advance, fall back, and then move forward again, all in incremental steps.

The American experiment in representative democracy is always a work in progress. The results are always in doubt. Lincoln’s words at Gettysburg — “whether a nation so conceived and so dedicated can long endure” — will probably resonate for as long as we’re a nation.

We face immense systemic problems at the moment:

• Racial discrimination
• Wage stagnation
• Staggering income inequality
• Political polarization
• The pernicious effects of too much money washing around in the system
• The degradation of civil discourse

It is not a given that we’ll be able to resolve them, and we always have to be alert to the fact that our freedoms and rights can be eroded.

To prevent this erosion, we have to step up to the task of responsible citizenship.

This is a challenge for every generation. As Americans we believe in a set of democratic ideals, basic rights, fundamental freedoms and the notion that all people are created equal and all are entitled to dignity. These are ideas that give us cohesiveness and identify us.

But we cannot take our ability to deliver on them for granted. Without a renewal of energy and commitment to the democratic values of the Constitution, without acting on the call issued by the Preamble, we could lose them.

Lee Hamilton is a Senior Adviser for the Indiana University Center on Representative Government; a Distinguished Scholar, IU School of Global and International Studies; and a Professor of Practice, IU School of Public and Environmental Affairs. He was a Democratic member of the U.S. House of Representatives for 34 years.