"I resign out of the firmly held belief that a representation should not be abandoned because the client's legal position is extremely unpopular in certain quarters. Defending unpopular clients is what lawyers do," Clement wrote in his resignation letter to King & Spalding chairman Robert Hays.
"I recognized from the outset that this statute implicates very sensitive issues that prompt strong views on both sides," Clement wrote. "But having undertaken the representation, I believe there is no honorable course for me but to complete it."
Said King and Spalding spokesman Les Zuke: "We're sorry to see Paul Clement leave. He's been a good partner, and we wish him the best."
In a statement, a spokesman for House Speaker John Boehner said he was "disappointed in the firm's decision and its careless disregard for its responsibilities to the House in this constitutional matter."
"At the same time, Mr. Clement has demonstrated legal integrity, and we are grateful for his decision to continue representing the House," Brendan Buck told TPM in a statement. "This move will ensure the constitutionality of this law is appropriately determined by the courts, rather than by the President unilaterally."
Zuke, a spokesman for King and Spalding, issued this statement to TPM and other media outlets on behalf of King and Spalding Chairman Robert D. Hays, Jr.:
Today the firm filed a motion to withdraw from its engagement to represent the Bipartisan Legal Advisory Group of the House of Representatives on the constitutional issues regarding Section III of the 1996 Defense of Marriage Act. Last week we worked diligently through the process required for withdrawal.
In reviewing this assignment further, I determined that the process used for vetting this engagement was inadequate. Ultimately I am responsible for any mistakes that occurred and apologize for the challenges this may have created.
Zuke declined to answer additional questions, telling TPM that the firm had nothing to add beyond the statement.
King and Spalding's decision came after pressure from gay groups, which issued statements praising King and Spalding for their decision.
"Today, we learned once again that it is a bad idea to defend antigay bias and discrimination in court, and fewer and fewer people are willing to do it," Lambda Legal Jon Davidson said. "We welcome the news that the law firm, King and Spalding, has decided to withdraw from the engagement to represent House leadership in defending DOMA. We were very surprised and disappointed when King and Spalding accepted this assignment, because they have been supporters of LGBT equality in the past."
"Some attorney will no doubt accept this job and defend DOMA in court on behalf of the House leaders - that's the way the legal system works," Davidson said. "We're just glad it is not a law firm that has shown respect and support for their own LGBT attorneys, for our community and for our fight for equality. We welcome the firm back to the right side of history."
[Ed. note: This story has been updated.]