Day 1 of the DNC began with the Pennsylvania delegation's breakfast. Speakers included Minnesota Governor Tim Walz, Governor Josh Shapiro, State Party Chair State Senator Sharif Street and Speaker of the Pennsylvania House, Joanna McClinton.
DNC Day 1 live updates: Biden arrives in Chicago; Democrats set to rally around Harris as nominee
Speakers maintained the enthusiasm the party has seen since Vice President Kamala Harris went to the top of the ticket and Walz became her running mate.
"We are here for the next few days to start the catalyst for change," said McClinton.
"The leadership of this party is getting people out. Vice President Harris bringing back what we know," said Walz to the crowd.
President Joe Biden is slated to speak Monday in a historic passing of the torch to Harris. While nearly 14.5 million voters elected Biden in the primary to run for president, he made the unprecedented decision to drop out and endorse Harris.
According to a new ABC News Washington Post Ipsis poll, Harris is pulling slightly ahead of Former President Donald Trump, including by one point in Pennsylvania.
READ MORE: Kamala Harris leads Donald Trump overall, but not on handling of the economy: POLL
Trump, however, is leading on issues like the economy, crime and safety, and immigration.
Democrats are leaning on policies they say Biden and Harris laid the groundwork for in their first administration, including health care.
In South Philadelphia, Vance grabbed a cheesesteak at Pat's and met supporters following a rally in North Philadelphia. He spoke about manufacturing and energy at DiSorb Systems.
Vance slammed Harris' recent proposals to lower food and home costs.
"She says on Day 1, she wants to make groceries and homes more affordable for American citizens. Kamala Harris, where have you been? You've been vice president for 1,300 days!" Vance told the crowd.
The visit to Philadelphia marks Vance's third time.
Trump also made a stop in York County, Pennsylvania.