Brian Steinberg Senior TV EditorDonna Brazile, the former chair of the Democratic National Committee and a veteran political operator, has joined ABC News as a contributor, a move that is likely to limit her appearances on Fox News Channel, where she has been appearing regularly since March of 2019.Brazile made a recent appeared on ABC News’ “This Week,” identified as a contributor, and a spokesperson for the Walt Disney unit confirmed she had joined its roster in previous weeks.