President Donald Trump on Thursday fired his embattled Homeland Security Secretary Kristi Noem and said he will nominate in her place Oklahoma Republican Sen. Markwayne Mullin.
Trump made the announcement on social media on Thursday, two days after Noem faced a grilling on Capitol Hill from GOP members as well as Democrats.
Trump says he’ll make Noem a “Special Envoy for The Shield of the Americas,” a new security initiative that he said would focus on the Western Hemisphere.
Edit: Here’s who is replacing her- https://en.wikipedia.org/wiki/Markwayne_Mullin#Personal_life
Mullin voted against reauthorization of the Violence Against Women Act in 2013.[93][94] His vote drew criticism from other Cherokee citizens in Indian Country Today.[94]


There will be a gap between Mullin taking the appointment and a new appointment coming in. During that time the GoP majority will be a vote short, which is a problem when they keep having to have Vance come in to break tie votes on their major policies.
The gap could be as small as almost being non-existent.
Trump said Mullin is taking over March 31st. So that’s basically a month for the Governor to find a replacement that requires no approvals of any kind. They could simply grab a previous failed Republican candidate from last election, that’s what most Governors do.