One candidate running for President (hint: the one who makes his own line of clothes in China) seems to thrive only when he’s attacking people who challenge or disagree with him. That approach ignores a simple fact: when we’re working together, the nation’s problems actually get fixed.

One of those problems that shouldn’t be associated with political party labels is transportation. From the transcontinental railroad to our elaborate highway system, presidents from both parties built infrastructure that was the envy of the world. These initiatives defined American economic strength and leadership for generations, and brought the world closer together in ways never before imagined. Massive investments in America’s mobility were not about making one political party look good and the other one look weak or ineffective. Quite the contrary — they were about launching America into an era of unprecedented growth and prosperity.

We linked cities and markets. We helped Americans get to and from work. We helped businesses sell their products and services. And we created a middle class that, for decades, defined American strength.

The truth is that not a single transformative investment in our transportation infrastructure occurred without bipartisan cooperation. The transcontinental railroad would not have been built without cooperation between President Lincoln and politicians across the political spectrum. Our national highway system was built because President Eisenhower worked with Democrats and Republicans in Congress to launch a surface transportation system that linked American communities — urban, rural and suburban — and created the world’s most comprehensive highway and bridge network.

Later, the political parties worked together with President Johnson to launch what today is a massive public transportation system that is a lifeline for businesses and public institutions of all sizes and their employees — a network without which America’s commuters would wither in traffic and dangerous air pollution.

Today, our national passenger railroad, Amtrak, which was created when President Nixon partnered with a bipartisan Congress, is seeing record ridership and growth. This system supports 20,000 middle-class jobs, gives Americans needed travel choices and spares the Northeast corridor from traffic chokepoints that would decimate a region where one in five Americans live.

Our aviation system, the world’s largest, would not handle almost half the world’s air traffic if not for decades of bipartisan cooperation. Together, the political parties built out an air traffic control system and airports that serve the nation, and bring the world closer together in a global economy that is increasingly interconnected and reliant on air travel.

America’s seaports and navigation channels didn’t become the hubs and arteries for exports, imports and significant job creation through partisan bickering by Democrats and Republicans. For decades, presidents from both parties and Congress, no matter who controlled the majority, made sure our nation had the maritime infrastructure it needed to compete in the world.

Fast forward to Day 3 of the Democratic Convention, it is about “working together.” To transportation unions and their members, working together isn’t just a theme or slogan — it is the foundation for everything our country has done to build out, maintain and modernize the transportation system where millions of Americans work, and that all of us rely on.

Donald Trump has talked about our crumbling infrastructure but has yet to put out a single proposal detailing what he will do to reverse the decay, and how he’ll pay for it. Instead, his platform takes a major step backward by calling for an end to mass transit funding and cuts to Amtrak. And the dangerous austerity it embraces gives us no hope that a Trump Administration will do anything but go along with the slash-and-burn, budget-cutting mentality that currently controls the House and Senate.

By contrast, Secretary Clinton has not only made it a priority to modernize our transportation system, but she has a plan to invest billions and put millions to work. She also knows from her policy experience that making big things happen requires bipartisan cooperation. She understands that insults will not repair or replace a single failing bridge or expand an aging and overburdened transit system.

Working together is what America needs right now if we are going to reverse a generation of austerity budgets that have left our transportation system on the brink of failure. Secretary Clinton — both her specific plans and her experiences — gives us that chance. Donald Trump threatens to further divide an already divided country by pitting Americans against each other and telling us that by scapegoating others we will make this country “great again.”

For transportation workers, working together means finally having a majority in Congress and a president who works together on behalf of the American people — the way previous leaders in both parties did. Working together is how big things get done — it is how we will get out of the transportation mess we are in. It is why we need Secretary Clinton to lead this country down a path of reconciliation and progress. Secretary Clinton can return us to a time when Democrats and Republicans worked together to build and maintain the world’s finest transportation system — a symbol of American strength, ingenuity and, yes, “greatness.”