Apple, along with dozens of major corporations, has signed a "friend-of-the-court" brief to the federal Supreme Court arguing that outside of the nine states where gay marriage is legal, the Defense of Marriage Act harms workplace morale and can undermine recruiting.

Other publicly traded companies that signed the brief include Facebook, Inte, Abercrombie & Fitch, Alcoa Inc., American International Group (AIG), Becton Dickinson & Co., EBay, Marsh & McLennan Cos., NCR Corp, Nike, Oracle, Office Depot, Panasonic, Qualcomm, Sun Life Financial, Xerox, Zynga, Barnes & Noble and Caesars Entertainment, Bloomberg reports. This move turns up the pressure on President Obama, who has to decide by Thursday whether or not to join this group, along with six formerly high-ranking Republican leaders, in arguing for the dismantling of the Defense of Marriage Act, which restricts federal tax benefits to married heterosexual couples.

Dozens of formerly high-ranking Republican leaders, including Jon M. Huntsman (former governor of Utah), Meg Whitman (who supported Prop 8 when she ran for office in California), Ileana Ros-Lehtinen of Florida and Richard Hanna from New York, Stephen Hadley, Carlos Gutierrez, James B. Comey, David A. Stockman and Deborah Pryce, recently broke ranks with the party to sign a brief in support of gay marriage, the NYTimes reports. This is in direct opposition to Speaker John Boehner and the party platform, which pretty uniformly rejects gay marriage across the board.

Most of these Republicans are, notably, no longer in office and therefore have no elections to lose, but Theodore B. Olson, who was the solicitor general under George Bush, is an influential conservative lawyer. He is one of two lead lawyers who will bring the case against DoMA, which was passed in 1996.

Other prominent Republicans who support same-sex marriage but have not yet signed the brief include Laura Bush, Dick Cheney and Colin Powell. Public opinion has changed rapidly in the last decade: a poll from 2003 showed that only one-third of Americans supported same-sex marriage, but these Americans are now the majority. Especially young people— 70 percent of voters under 30 — support same-sex marriage.

"Friend-of-the-court" briefs rarely change judges' minds, but the justices can take the briefs into account when they make their ruling.