Watch Pete Buttigieg answer questions at a CNN Town Hall on Sunday at 9 p.m. ET. Buttigieg, a candidate for the Democratic nomination for president, is the mayor of South Bend, Indiana. The opinions expressed in this commentary are his own; view more opinion at CNN.

(CNN) The 2020 election is about more than just the next four years and defeating Donald Trump. It must address the seismic changes our nation is facing -- both globally and at home -- and ensure every American has the opportunity to succeed.

I understand the importance of confronting daunting changes head-on. When I was running for mayor of South Bend, Indiana, in 2011, Newsweek named our city one of "America's Dying Cities." Decades prior, we had been a great industrial center, home to the auto giant Studebaker and a dozen other major companies. But after decades of population decline, many were ready to write us off.

In the eight years since I was first elected, we've experienced one of the fastest population and investment growth periods in a quarter of a century. We changed our trajectory as we dealt with vacant and abandoned houses , created thousands of new jobs, grew our population, and came to believe in ourselves and our future again.

Former factory districts are adding jobs in data centers and turbomachinery research -- industries that didn't even exist when the last Studebaker rolled off the line. And we still make things. Our advanced manufacturing workers are sending their products to Asia, not their jobs.

And we didn't do it by looking to the past for greatness. We understood that honest politics can't revolve around the word "again." The message from the start was: "The Studebaker plant isn't coming back, but we are, and here's how." We were able to change our city's path by preparing people for change and showing them a world where change meant progress and success.

The advances we've made in South Bend serve as a shining example at this point in our nation's history, especially when Americans have been offered a vision of greatness that means turning back the clock. We need big, bold policies that are shaped by what we want our country to look like generations from now.As a country, we're facing deep structural problems that can only be addressed by fixing the engine of our democracy. The reality is that every other important issue of our time -- from gun violence to climate change to access to healthcare -- isn't going to get better as long as our democracy remains warped. Our freedom depends on our ability to make bold changes.

What does that mean? For starters, we need to re-evaluate the role of the Electoral College, which has -- in my short lifetime -- overruled the popular vote twice. It should be a commonsense position that the person who gets the most votes is the person who wins the presidency. We also need to make it easier for people to vote, so we don't wind up seeing the US become less democratic on our watch. That's why I'd prioritize finally giving our fellow US citizens in Puerto Rico and Washington, D.C., real representation and a real voice in the national political process.

Freedom should be the organizing principle for our domestic policy, but leaders in my party have relinquished the language of freedom to the right. Conservatives care about freedom, but their attention is limited to freedom from government or freedom from regulation. But there's more to freedom than that.

There needs to be the freedom to focus on family or faith, or any of the things that matter most in life -- which just isn't possible when you're worried about where to get clean, safe drinking water.

You're not free if you can't sue a financial institution that gets caught ripping you off. You're not free if you can't start a small business because you fear losing your health care, and you're certainly not free if a male boss or politician prevents you from making decisions about your own reproductive health. You're not free if you can't marry the person you love because a county clerk is imposing his or her interpretation of religion on you.

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When I think about what this country will look like in 2054 (when I will be the same age as our current president), I know that the decisions we make in this moment will determine the freedoms future generations have.

We will not find greatness in the past, trying to dredge it up from some impossible "again." Greatness will come by looking forward -- untethered from the politics of the past and anchored by our shared values -- and by changing our nation's future.