Democratic vice presidential nominee Kamala D. Harris said Sunday that she thinks Russian interference could cause Democratic presidential nominee Joseph R. Biden to lose the 2020 election. Ms. Harris told CNN that Russia will be at the “front of the line” to interfere in the 2020 election. “Could it cost you the White House?” asked CNN personality Dana Bash about Russian election meddling to Ms. Harris. “Theoretically of course,” Ms. Harris answered. “Yes.” Ms. Harris, a member of the Senate Intelligence Committee, said she and Mr. Biden are ‘realists’ that refuse to ignore Russian aggression. She did not say what...