This report comes from PunchUp, a Daily Beast newsletter from veteran reporter Tom Latchem (paywall, that we paid, so that we might tell you things):

President Donald Trump invented a senior government role for Kristi Noem to stop her from running for a seat in the Senate this year, administration sources tell PunchUp,

The title of “Special Envoy for the Shield of the Americas”—announced on March 5 by Trump, 79, as he publicly fired Noem from her role as DHS secretary—was effectively fabricated to ensure she missed the filing deadline for the South Dakota Senate race and would thus be unable to challenge incumbent Sen. Mike Rounds, according to multiple sources.

“It was made up to keep her busy,” one source close to the administration told PunchUp of Noem’s new role. The source said the White House’s private view was that Noem had become so toxic it needed to “put her out to the glue factory”—and so invented an opening that kept her on the government payroll and off the ballot, but with no real power.

...

To secure a place on the primary ballot, Noem would have needed to collect 2,171 petition signatures and file them by 5 p.m. on March 31.

She had 26 days but no time, as she threw herself into her new job, with sources saying that Noem felt she had no choice but to show her willingness to toe the president’s line.

...
This is all … oh my God. They tried to unring the bell by having her report to one of Rubio’s underlings instead of Rubio himself. That guy, Deputy Secretary of State Chris Landau, “has now nuked the whole thing,” says Latchem’s source in the administration.

She tried to bring 10 staffers along to her fake job. Three have already been fired, from even more fake jobs. The ostensible reason for their firing from fake jobs? Because they were Lewandowski loyalists. But really, says Latchem?

https://www.wonkette.com/p/trump-made-up-fake-power-ranger-fairy