Original link: Kristi Noem out as DHS secretary, Trump taps Sen. Markwayne Mullin to replace her / CNN.
First Tom Homan replaced Gregory Bovino as the one handling deportations. Likely because Tom Homan knows how to deport illegal immigrants while Gregory Bovino seems better at sending heavily armed police officer on the street of US cities to be photographed and draw protests.
And now Kristi Noem get replaced by a senator Markwayne Mullin. Likely because Markwayne Mullin knows how to work with congress and state governments while Kristi Noem seems better at appearing tough on social media.