Explainer - Trump risks legal fight with emergency threat on wall

WASHINGTON (Reuters) - President Donald Trump would almost certainly face a legal challenge if he makes good on his threat to get funding for a U.S.-Mexico border wall by declaring a national emergency and circumventing Congress's purse-strings power.

Legal scholars said it was unclear how such a step would play out, but they agreed a court test would likely focus on whether an emergency actually exists on the southern border and on the limits of presidential power over taxpayer funds.