Argentina's President Javier Milei has elevated Diego Santilli to chief of staff with expanded authority over both the Interior Ministry and congressional relations—powers no previous chief of staff has held simultaneously since the position's creation in 1994. The move marks a shift in Milei's inner-circle dynamics as he faces declining approval below 40% and prepares for 2025 reelection, navigating competing visions between his sister Karina and adviser Santiago Caputo over whether to build a broader provincial coalition or run exclusively with Milei's movement candidates.