Following Republicans' major losses in the US midterm elections, Donald Trump has replaced longtime chief of staff Susie Wiles with close adviser Stephen Miller, a key architect of his immigration policies and a prominent voice in his administration and the MAGA movement.

The move comes as Trump enters the final two years of his second term facing a Democratic-controlled Congress and growing pressure over issues such as the economy and the war in Iran.

Political scientist Timothy Hagle explains what the reshuffle could mean for Trump's agenda, executive powers and political legacy.