make the u.s. more reliant on foreign resources. >> bret: president biden's campaign is trying to gain points focusing on former president donald trump's mental fitness. this comes as his team fights back against public doubts about president biden's cognitive abilities. there is also increasing concern by democrats about the third party challenge from robert f. kennedy jr. and disagreement among republicans about early voting. all of that correspondent bryan llenas shows us tonight from philadelphia. >> the trump campaign and the republican national committee launching a new election integrity program they call monumental. committing to deploy over 100,000 volunteers and, quote: aggressive attorneys across every battleground state. in an effort they say to ensure transparency and fairness in the 2024 elections. in a memo last month, the rnc said that encouraging voters to