ABC News' Ariane de Vogue reports: Powerhouse lawyer Paul Clement is not only representing the House of Representatives in its defense of the Defense of Marriage Act (DOMA), he is also the chief lawyer tasked with representing 26 states in a bid to have an appeals court strike down the Obama administration’s health care law. Clement recently resigned from his top shelf law firm, King & Spalding, when the firm abruptly reversed a decision to provide legal services to defend DOMA — the federal law that defines marriage as being between a man and a woman.The firm was facing protests from gay rights groups for its stance in the case. In his resignation letter Clement said that he "recognized from the outset" that the statute implicates sensitive issues "on both sides" but that "having undertaken the representation, I believe there is no honorable course for me but to complete it." He also announced he would join the firm of Bancroft PLLC. Today, Clement filed his first brief in the health care case, arguing that the law “rests on unprecedented assertions of federal power.” He says the law “pushes even the most expansive conception of the federal government’s constitutional powers past the breaking point.” Arguments are set for June 8th.