Democrats are trying to make inroads with voters on immigration and border security.
A recent one ABC News poll found that Donald Trump maintains the upper hand on the issue, making the race still contested.
Trump leads Harris by 10 points in trust to handle the immigration situation at the US-Mexico border, although he had led by 14 points in July.
At the DNC, speakers are slamming Trump for encouraging congressional Republicans to kill the bipartisan border deal negotiated earlier this year.
“He’s a self-serving man,” said Javier Salazar, the sheriff of Bexar County, Texas, right on stage. “Just like when he killed the border bill, he just made our jobs harder.”