President Trump has declared a national emergency to build a wall on the border with Mexico. But an array of groups are preparing legal challenges to stop him. Here’s who they are, and what chances they have.

President Trump has declared a national emergency to build a wall on the border with Mexico. But an array of groups are preparing legal challenges to stop him. Here’s who they are, and what chances they have. https://t.co/yEXwnGBP6P

— NYT National News (@NYTNational) February 16, 2019