By Victoria Reggie Kennedy

I support Hillary Clinton to be the nominee of the Democratic Party and the next President of the United States. I know her well and have seen first-hand her dedication and determination to improve lives and expand opportunity for our fellow Americans.

I first witnessed her commitment to comprehensive health care reform when she headed a task force at the dawn of the Bill Clinton Administration in 1993. At that point, my husband Senator Edward Kennedy had been working for comprehensive health care reform for more than 20 years. As he wrote in his memoir True Compass, the notion that a president was so committed to health care that he would put his extraordinarily capable wife in charge of sweeping reform was "thrilling, perhaps even revolutionary."

Teddy told me how much he admired Hillary's tenacity and willingness to tackle such a difficult but necessary issue in the face of such strong political opposition to change. Though the effort at that time for comprehensive change was ultimately unsuccessful, the issue had been joined and it would not go away.

When the opportunity arose to expand health insurance to children, Teddy turned to Hillary for support and advocacy. She worked with my husband on a bipartisan bill to extend health coverage to otherwise uninsured children. Together, they expanded health insurance to eight million children nationwide. Hillary shared with Teddy the belief that you should look for common ground and seize the moment to help as many people as possible - especially children.

In 2008, Teddy was convinced that the time finally had arrived for comprehensive reform. By then, Senator Hillary Clinton was a member of the Senate Health Committee that my husband chaired. I was with him when Senator Clinton called to discuss her strong, ongoing commitment to healthcare and her desire to be actively involved in the passage of what became the Affordable Care Act. Even after President Obama chose her to become his Secretary of State, I know she remained unwavering in her support of the ACA.

Teddy's 40-year quest for comprehensive healthcare reform finally seemed within reach. But my husband was fighting cancer by then, and it was becoming clear he wouldn't see his dream come to pass. So he urged all of us to fight on, saying that if we didn't seize this moment, we would lose the opportunity for another generation.

Although I was heartbroken that my husband was not there, I was proud to stand at President Obama's side as he signed the Affordable Care Act into law. Because of the hard work of so many, including Hillary Clinton and Ted Kennedy, nearly 20 million more people are now insured. Young people can stay on their parents' policies until they're 26. Women are no longer discriminated against with higher rates just because of their gender. Preventive care for the first time is written into our healthcare system. And we can't be denied insurance because of a pre-existing condition or dropped from coverage when we get sick.

Change has not been easy. And I have no doubt that if Teddy were here, he would be roaring about improvements he wanted to make. I also have no doubt that he would be roaring even louder about the success of this legislation in giving millions of Americans a sense of health security they never had before.

Many times, and as recently as 2007, Teddy routinely introduced a Senate bill to provide for single payer health insurance. While he explained to me that he believed in it, he also understood political realities. The votes were not there - and were not going to be any time soon. So, on a parallel track, he aggressively pursued other avenues for health reform. He said his goal was not perpetually to search for the impossible, but rather to help improve lives and make a difference.

Ted Kennedy called healthcare the cause of his life, and he strongly supported the Affordable Care Act. In that spirit, I stand with Hillary Clinton and her goal to strengthen and improve this landmark legislation.

Every election is about the future, and this election is no exception. We don't need to open up old wounds to refight health care reform.

It's time to move forward. We need a 45th President who will continue to fight for the Affordable Care Act and make it even better. We need Hillary Clinton.

Victoria Reggie Kennedy, the widow of Senator Edward M. Kennedy (D-MA), is an attorney.