Biden 'fights back tears' as Kamala Harris speaks about her friendship with his late son Beau

Joe Biden 'fought back tears' as he listened to Kamala Harris' heartfelt recollection of her friendship with his son.

Harris and Beau Biden were both US senators in the early 2010s and worked together to negotiate with American banks during the foreclosure crisis. She wrote in her memoir that there were periods when "Beau and I talked every day, sometimes multiple times a day" on the phone, and that he was an "incredible friend and colleague".

When Beau Biden died of brain cancer in 2015, at 46 years old, Biden and Harris shared in their grief over the loss.

During her first speech as Biden's running mate, Harris reflected on their time together.

Ever since I received Joe’s call, I’ve been thinking about the first Biden that I really came to know and that, of course, was Joe’s beloved son — one of his beloved sons — Beau.

I learned quickly that Beau was the kind of guy who inspired people to be a better version of themselves. He really was the best of us. And when I would ask him, where’d you get that? Where did this come from, he’d always talk about his dad.

And I will tell you that the love that they shared was incredible to watch. It was the most beautiful display of the love between a father and a son.

And Beau would talk about how Joe would spend four hours every day riding the rails back and forth from Bloomington to Washington so he could make breakfast for his kids in the morning and make it home in time to tuck them in bed each night.

All of this so two little boys, who had just lost their mom and their sister in a tragic accident, would know that the world was still turning.

Biden's first wife, Neilia Hunter, and his one year-old daughter Naomi, were killed in a traffic collision in 1972. His sons Hunter and Beau Biden survived the crash.

According to reporters present during Harris' speech, Biden "fought back tears" as he listened from the back of the stage.

Biden and Harris were united over their love for Beau Biden.

In the lead up to announcing his choice of running mate, Biden wrote that he "thought a lot" about Harris' friendship with his son.

He wrote in a campaign email:

There is no one’s opinion I valued more than Beau’s and I’m proud to have Kamala standing with me on this campaign.

Elsewhere in her speech, Harris tore into Trump and his presidency, calling it a "failed government".