A huge list of America's top corporations are jumping headfirst into the marriage equality debate, signing an amicus brief that urges the Supreme Court to make same sex marriage a legal right for the entire country.

In their brief (an amicus brief is essentially an argument filed with the court in support of a party in a Supreme Court case), the 379 companies — including Twitter, Facebook, Google, Amazon, and more — laid out why their businesses benefit from countrywide, universally acknowledged marriage equality. Outlining the separate-but-equal-is-not-equal argument, they then made the case for how a lack of marriage equality countrywide hampers their ability to hire the best talent available. If they can't offer the same benefits and compensation packages to all of their employees, how are they supposed to stay competitive? There is nothing separate-but-equal about someone's partner not being allowed access to their husband or wife's health insurance, for example.

"State laws that prohibit or decline to recognize marriages between same-sex couples hamper employer efforts to recruit and retain the most talented workforce possible in those states," the brief states. "Our successes depend upon the welfare and morale of all employees, without distinction."

And not only that, having to finagle these murky waters causes extra, often confusing, work for the administrators themselves.

"Some of the states in which [we] do business make marriage equally available to all of our employees and colleagues; others prohibit marriages between couples of the same sex and refuse to recognize existing same-sex marriages," the brief reads. "This dual regime burdens [businesses]. It creates legal uncertainty and imposes unnecessary costs and administrative complexities on employers, and requires differential employer treatment of employees who are similarly situated save for the state where they reside." 

Because of that, employees in same-sex relationships receive varying levels of access to the rights, benefits, and privileges afforded to more traditional male/female couples. This undermines the corporate culture at large, the brief argues, by driving talent away to states with less restrictive laws while simultaneously creating an air of resentment and frustration between colleagues themselves. 

While the humiliation, stress, and frustration cost may be one that's largely unquantifiable, the companies claim it does lead to something a bit more calculable. This human cost ultimately leads to an "economic burden on American businesses at an estimated cost of over one billion dollars per year," according to the brief. 

The Supreme Court will hear arguments regarding the constitutionality of the state-based, same-sex marraige bans on April 28th, and their decision is expected in June.