Almost two years ago I announced I was not going to seek a sixth term in the United States Senate. That decision and announcement did not seem all that difficult or hard at that time.

Two years was a long time off. And since then I have been busy working, having hearings, meeting constituents, getting legislation through the HELP Committee, working on Appropriations.

But, now, the leaving becomes hard and wrenching and yes, emotional. That’s because I love this U.S. Senate and I love this work. Often, I am asked if there is one theme, one unifying thread that runs through my body of legislative work across 40 years in Congress.

At first glance, my policy priorities seem to be disconnected and disparate, everything from disability rights to health reform to farmland conservation to biomedical research. But on closer examination, they all have one powerful thing in common; they all flow from a common wellspring. And for you to understand that unifying inspiration, I need to tell you a story.

As a boy growing up in rural Cumming I could never have imagined that I would one day serve in Congress. My father had a sixth grade education. He spent most of his life working in coal mines, and all he had to show for it was a case of black lung disease. My mother was an immigrant, raising six kids in our little two-bedroom house.

My parents never talked politics. We did not know politicians. But we knew this: When my family hit rock bottom in the late years of the Depression, with my father out of work and with no way to provide for his family, the government gave us a hand up. Dad got a postcard in the mail, notifying him to report for employment with the Work Projects Administration, the WPA. Dad always said that Franklin Roosevelt gave him a job. That opportunity gave my father dignity, and enough money to put food on the table. Perhaps most importantly of all, it gave him hope.

A few years later, dad was able to qualify for a New Deal program called Social Security, and later he got Medicare, which meant he no longer had to rely on charity. So I learned at an early age that our government can do good things and create opportunity for ordinary people. It is there to help people build better lives. And from my first day in the political arena, I have strongly believed that government must not be just an observant bystander. It must be a force for good, for lifting people up, for giving hope to the hopeless. Its cardinal function is to provide a ladder of opportunity for every American.

Now, as I depart the Senate, I can say in good conscience that I remained true to that guiding principle. I have worked faithfully to leave behind a more vibrant Iowa, a more just and inclusive America, and a stronger ladder – and ramp – of opportunity for the disadvantaged in this great country.

Let me reassure you that though I am retiring from the Senate, I am not retiring from the fight. I will never retire from the fight to ensure equal opportunity, full participation, independent living, and economic self-sufficiency for people with disabilities. I will never retire from the fight to give a hand up – and hope – to those who have experienced disadvantage and adversity. And I will never retire from the fight to make this a land of social and economic justice for all Americans.

You might say that my career in Congress is the story of a poor kid from Cumming, Iowa trying his best to “pay it forward,” saying thank you for the opportunities I was given by leaving that ladder and ramp of opportunity stronger for those who follow. If I have accomplished this in any small way, if many Iowans and many Americans are able to lead better lives because of my work, I leave office a satisfied man.

For that opportunity, I must thank my fellow Iowans.

Thank you for giving me the opportunity to do this work.

Thank you for entrusting me with the job of advocating for the betterment of our state and country for the past 40 years. It has been the greatest honor of my lifetime.