Kristi Noem’s assertion at a Senate hearing Tuesday that President Trump had given his blessing to a $220 million Department of Homeland Security (DHS) advertising campaign promoting Noem’s leadership was the final straw that cost the DHS secretary her job on Thursday, according to Republican senators and other sources familiar with the events.

Trump considered firing Noem after the fatal shootings of two protesters by federal officers in Minneapolis in January, but he held off because he didn’t want to appear as giving in to Democrats’ demands for her resignation, according to sources familiar with Trump’s deliberations.  

There’s been conversations going on, I think, for a while and I haven’t been privy to all of them but I’m aware of some of the discussions,” he said.

One GOP senator who requested anonymity said that Noem’s claim that Trump personally approved the controversial ads was the “last straw” because it had the effect of “dragging” the president into a potential scandal.

The $220 million taxpayer-funded advertising campaign has come under scrutiny because the Department of Homeland Security skipped the normal competitive bidding process and awarded the ad to the Strategy Group, a firm that has ties to Noem’s political operation.

Sen. Thom Tillis (R-N.C.), a member of the Judiciary Committee, said the appearance that Noem may have steered business to friends and allies is troubling.

“I think there are appearances we’ll have to work through,” he said. “I’ve got to believe some of those factors weighed into the ultimate decision in the White House.”

It certainly looks bad,” he said.

Tillis said he didn’t buy Noem’s explanation that she was not closely involved in awarding the contract given that she has established a policy at the Department of Homeland Security requiring her to personally review all contracts worth more than $100,000.

“The problem is she undermined her own credibility by saying she reviews everything in detail … but she knew nothing about a $200 million transaction. How do you work those two?” he said.