Even Vice President Kamala Harris’ supporters fear she hasn’t been able to define her leadership credentials as the 2024 election looms amid questions about President Biden’s age and ability to serve, with one Democrat remarking, “I can’t think of one thing she’s done,” according to a new report. Harris made history in 2020 when she was elected the first black and first Asian American vice president, but has struggled while in office with frequent staff turnover — coupled with reports of a toxic office environment — along with frequent gaffes and “word salad” statements, and criticism of her work as...