Coffman, a moderate representing a swing district in and around Aurora, was asked at a town hall about Spicer's remarks this week that even Hitler didn't "sink to using chemical weapons" during the Holocaust.
While Hitler is believed not to have used chemical weapons on the battlefield, the Nazis used Zyklon B and other types of poison in gas chambers to kill millions of Jews in concentration camps. He followed that up by telling reporters that Hitler brought Jews "into the Holocaust center", but he "was not using the gas on his own people in the same way that Assad is doing", referring to the Syrian dictator. "I think it was a really poor illustration that (Spicer) apologized for".
Mr Spicer said his comments were professionally upsetting because President Donald Trump had had "an unbelievable successful couple of weeks" and it was his job to amplify that message of accomplishment but "I've let the president down". "I got into a topic I shouldn't have", said Spicer.
And on Wednesday morning the press secretary said: 'I screwed up.
Following Spicer's comments on Tuesday, some Democrats including House Speaker Nancy Pelosi called on Spicer to resign.
During an interview at the Newseum in D.C., Spicer said he let the president down, and asked the public to forgive a mistake he calls both offensive and inappropriate. "Any attack on innocent people is reprehensible and inexcusable", according to the Huffington Post.
He noted that Trump had bombed a Syrian air base in a forceful response to chemical weapons use by Assad's government and said Trump's hosting of Chinese President Xi Jinping last week had produced "tremendous progress".
"This was my mistake, my bad, that I needed to fix", Spicer added.
'But if I'm President Trump, I'm like, well Jesus Christ, we're a laughingstock'.
For decades, the ADL has provided trainings about the Nazi atrocities and the Holocaust to hundreds of thousands of students, educators and law enforcement officials, Greenblatt said.
"I sought people's forgiveness because I screwed up", he said in a subdued tone while seated next to Van Susteren. "I remember all the awful pictures coming out of World War I from battlefield use of gas and the gas masks and what it did to people".