Last Updated Jun 6, 2018 7:51 PM EDT
Sen. Joni Ernst told CBSN on Wednesday she thinks embattled Environmental Protection Agency head Scott Pruitt "did lie" when he seemingly reneged on a letter pledging to promote ethanol, saying the EPA chief is "undercutting" President Trump's commitment to farmers.
The Iowa Republican's comments came after she described Pruitt as "about as swampy as you get" earlier this week. Ernst told CBS News correspondent Errol Barnett on Thursday that Pruitt has "moved entirely away" from a letter she says he signed last year indicating he would move away from attaching renewable identification numbers to ethanol exports from the U.S. In Ernst's eyes, Pruitt's failure to promote the Renewable Fuel Standard equates to him failing the president and his promises, she said.
"So I do think that he did lie," Ernst said. "He put his name to this letter and then did exactly he opposite. And that's what I mean by undercutting our president and our president's commitment to farmers."
Ernst stopped short of saying the president should fire Pruitt, saying that decision is up to the president. But she emphasized that Mr. Trump is serving America's farmers well -- and Pruitt is not.
"Well I do believe that the president should have the best qualified people serving his administration and certainly on his cabinet," Ernst said.
"And I think that the president has been doing a tremendous job. Just look at our economy and everything he's been able to accomplish. But if you look at Administrator Pruitt, especially when it comes to the issue of the renewable fuel standard, i just feel like the administrator is trying to undermine the president's promises to American farmers. And so I don't like that aspect. It is up to the president to decide who he wants on his cabinet. But certainly I believe that Scott Pruitt is not upholding the president's promises."
But Ernst also commented on the growing number of controversies involving Pruitt. In recent months, he has been criticized for the millions spent on his security, the condo he rented connected to a lobbyist with business before the EPA, for a $43,000 sound-proof phone booth and more. In this week alone, reports emerged that Pruitt asked a now-departing top aide to look for aand had his aide ask about a .
"If you take a look at the record of course, Administrator Pruitt has had some good wins for the EPA," she said.
"But there are some things that I disagree with him on and one was the renewable fuel standard. But outside of that...I promised the people of Iowa I would make them squeal here in the D.C. and when you look at some of the transgressions that we have heard about within the Pruitt administration, I think all of our American taxpayers would be very disappointed form that aspect. So certainly would like to see the administrator do a lot better. So that's what I mean by swampy."
Barnett asked Ernst what she would do if someone on her staff used taxpayer dollars for personal gain.
"They would not be on my staff any longer, that is guaranteed," she said.