On Thursday, dozens of American corporations, including Apple, Alcoa, Facebook, eBay, Intel, and Morgan Stanley will submit an amicus brief in the landmark Hollingsworth v. Perry case broadly arguing to the U.S. Supreme Court that laws banning same-sex marriages, like California's ballot initiative Proposition 8, are unconstitutional under the Due Process and Equal Protection Clauses. According to a draft copy obtained by Fortune, the companies argue that such laws "send an unmistakeable signal that same-sex couples are in some way inferior to opposite-sex couples, a proposition that is anathema to amici's commitment to equality and fair treatment to all." At...