WASHINGTON -- Colorado Republican Senate candidate and Tea Party favorite Ken Buck last year said he "strongly" disagrees with one of the bedrock principles of American society: the separation of church and state.

"I disagree strongly with the concept of separation of church and state," said Buck at a forum for GOP Senate candidates last year. "It was not written into the Constitution. While we have a Constitution that is very strong in the sense that we are not gonna have a religion that's sanctioned by the government, it doesn't mean that we need to have a separation between government and religion. And so that, that concerns me a great deal."

In his statement, he also criticized President Obama for calling the White House Christmas tree a "holiday tree." "It's just flat wrong in my mind," he added. His remarks were captured by the site ThinkProgress, which also has video.

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As former solicitor general Paul Clement points out, the phrase "separation of church and state" is not technically in the First Amendment. It's a phrase coined by Thomas Jefferson, who wrote in 1801 that "religion is a matter which lies solely between Man & his God" and argued the Constitution required "building a wall of separation between Church & State." But as ThinkProgress' George Zornick notes, the Constitution does prohibit the endorsement or establishment of a state religion.

This issue of "separation of church and state" also recently tripped up Senate Republican candidates Sharron Angle and Christine O'Donnell. In a June interview, Angle denied that the "separation of church and state arises out of the Constitution."

"Thomas Jefferson has been misquoted, like I've been misquoted, out of context," said Angle. "Thomas Jefferson was actually addressing a church and telling them through his address that there had been a wall of separation put up between the church and the state precisely to protect the church from being taken over by a state religion. That's what they meant by that. They didn't mean we couldn't bring our values to the political forum."

More recently, in a Delaware Senate debate, O'Donnell asked, "Where in the Constitution is the separation of church and state?" When Coons responded that the First Amendment bars the government from making laws respecting the establishment of religion, O'Donnell replied, "You're telling me that's in the First Amendment?" The audience audibly gasped.

Additionally, as FactCheck.org has documented, Buck's claim about the White House Christmas tree is "hooey." The Huffington Post contacted the Buck campaign for comment but did not receive a reply.

UPDATE, 12:17 p.m.: At a July 12 Tea Party meeting, Buck said that "the secularism that is developing in this country is a very scary concept." He has also advocated for the public posting of the 10 Commandments. As a Windsor 912 meeting on June 3, Buck explained in more detail his thoughts on separation of church and state:

Yes, we have separation of church and state. We don't want a state-sponsored religion, but no it doesn't mean that churches and government should never interact, and that wall that people are trying to form between the two and punish religion is something that I think has gone in the wrong direction, and I think what President Bush did with faith-based programs that worked with the government is exactly the right idea.