Transcript for Joe Biden holding 1st major campaign rally in a key battleground state
Well, now to democratic presidential hopefuls hitting the campaign trial. Former vice president Joe Biden holding his first campaign rally in a key battle ground state. Stephanie Ramos with the latest. Hello, Philadelphia. Reporter: Former vice president Joe Biden holding his first official presidential campaign rally in the city of brotherly love. The event in Philadelphia rich in symbolism. The reason we're here, is because in a literal sense, this was the birthplace of our democracy. Reporter: In the expanding democratic field the front-runner addressing the country's political divide and blaming president trump. This politics is pulling us apart. It's ripping this country apart at the seams and our president is the divider in chief. Reporter: Biden promising to unite the country. One of to core principles of his campaign. I'm running for Democrats, Republicans and independents. Reporter: At the rally I asked him about one of president trump's main issues, illegal immigration. Do you think there is a crisis at the border? No. I think the crisis at the border is the way they're treating people who are seeking asylum. Reporter: This theme echoed on the campaign trial. We must never, ever yank babies out of the arms of their mothers at the borders. Reporter: And mayor Pete buttigieg in Iowa. What kind of country locks people up fleeing what we're fighting. Reporter: Pennsylvania is a key state in the 2020 election. The candidates know it. President trump knows it. He'll hold a rally in state on Monday which he won in 2016 which he won by 1 less than 1%. As for Biden, his team tells me he'll travel to Florida, Tennessee and Texas in the coming weeks. But, guys, Biden's team they're really banking on Pennsylvania to back him up. Eva. All right, Stephanie, thank you.
This transcript has been automatically generated and may not be 100% accurate.