My organization, Equal Citizens, is working with a bipartisan team of lawyers that filed legal challenges to the winner-take-all system last month in four states — California, Massachusetts, Texas and South Carolina. Equal Citizens also ran a crowd-funding campaign to support the project and developed the legal theories underlying the lawsuits.

The challenge for winner-take-all’s defenders is serious. If we take away the “we’ve always done it that way” argument (doesn’t matter legally), the “it’s in the Constitution” argument (winner-take-all’s not in there) and the “states can choose presidential electors however they want” argument (they can’t, because they need to comply with “one person, one vote”), then the foundation for our current system starts to look less stable. In fact, our system crumbles.

It turns out there is no argument that can legally justify states’ use of winner-take-all to allocate electors. It’s an unconstitutional way to pick the presidential electors who ultimately cast votes for president and vice president.