Amid the controversy over President Donald Trump’s declaration of a national emergency at the Mexico border, a small cadre of Yale Law students has been key in arming a bipartisan group of national security heavyweights to oppose the move.

Sixty former national security officials, including former Secretaries of State Madeleine Albright and John Kerry and former Defense Secretary Chuck Hagel, this week released joint declaration laying out their myriad arguments against Trump’s emergency declaration in hopes of swaying lawmakers to oppose it.