It’s official, Joe Biden has selected Senator Kamala Harris (D-CA) to be his running mate.

Harris endorsed Biden back on March 8th saying, “Joe Biden has served our country with dignity and we need him now more than ever. I will do everything in my power to help elect him the next President of the United States.”

But it wasn’t always smooth sailing for the politicians. Back in June 2019, the two had a tense exchange during a Democratic debate as Harris called Biden out for his history on racial issues saying:

I do not believe you are a racist… But I also believe, and it’s personal — and I was actually very — it was hurtful to hear you talk about the reputations of two United States senators who built their reputations and career on the segregation of race in this country. And it was not only that, but you also worked with them to oppose busing.

Just a couple of weeks ago, Politico reported: “It’s difficult to overstate the bad blood that flowed between the Harris and Biden campaigns immediately after that June 2019 debate.”

That said, Harris was long seen as the front runner and a safe choice. She was also seen as someone qualified for the job. She was District Attorney of San Francisco from 2004–2011 and Attorney General of California for the following six years until being elected to the Senate in late 2016. NPR recently wrote that Harris’s allies saw “her prosecutorial résumé as the ideal professional background in a political climate intensely focused on racial justice and policing, and her reputation as a sharp attack dog in Senate hearings as a key asset for a running mate.” And, of course, the 55-year-old’s presidential run was also said to be a factor.

Biden and Harris are expected to deliver remarks tomorrow from Wilmington, Delaware.