The Minnesota Democrat said when he hears other lawmakers suggesting Christian Syrian refugees should be allowed into the country but Muslim Syrian refugees should not, it reminds him that the First Amendment to the Constitution establishes freedom of religion.
"I'm telling you that these folks are letting fear make them forget our Constitution, and they shouldn't do it," Ellison said Wednesday on MSNBC. "The fact of the matter is, we don't do that. That's not who we are as a nation."
He also called it a "big mistake" strategically, as it plays into ISIS' narrative that Islam is at war with the West.
Ellison also said that Muslim-Americans have many feelings about the anti-Islam sentiment, but that their biggest loyalty is to their home country.
"People feel fear, trepidation, hurt feelings, but you know what mostly the prevalent feeling is? A surge of patriotism," Ellison said.
He continued: "It's like, 'Wait a minute, I'm an American too. This is my country too. I'm here because I love this country, I'll fight for it, I'll die for it, and I'm not going to let ISIS ruin things for Muslims around the world.' I'm feeling a resurgence and a need to really kind of assert a Muslim-Americanness and tolerance and inclusion and respect."
Earlier, on CNN's "New Day," Ellison told Alisyn Camerota that rather than rush to act to close itself, the U.S. should provide a model of openness to counteract ISIS' message that the West is anti-Muslim.
"I don't think it's time for us to panic, I think it's time for us to confront Daesh, disrupt their false narrative demonstrate to the world that the West is the one that's compassionate, that they are the ones who are pitiless and merciless, and we need to confront them in every possible way," Ellison, using another term for ISIS, said on CNN.
He also predicted that House Speaker Paul Ryan will likely prevail in his attempt this week to pass legislation in the House suspending the Syrian refugee program, but Ellison hopes he won't.
"Who knows?" Ellison said of the vote outcome. "The fact is is that Paul Ryan is the head of the Republicans who is the majority, so that might give you some indication ... he may have some support."
"My question to him and everybody else is this: Do you really want Daesh to dictate terms to the United States?" he added.