White House senior adviser Stephen Miller appeared on Fox News Sunday to defend President Trump's Friday declaration of a national emergency to obtain funding for border wall construction — and host Chris Wallace did not let him off lightly.

"The president talks about an 'invasion' — he used that word multiple times on Friday — an 'invasion' on the southern border," Wallace said. "But let's look at the facts," he continued, citing statistics to show illegal border crossings have fallen dramatically in the last two decades; that the vast majority of heroin and fentanyl seizures at the border take place at official entry points, not unfenced areas; and that visa overstays now account for twice as many illegal entries to the United States as illicit border crossings.

"Again," Wallace concluded, "where's the national emergency to build a wall?"

After promising to address every fact Wallace raised, Miller responded by arguing that would-be illegal immigrants are now sneakier and more difficult to deport than they were two decades ago and that more drugs are not captured in unfenced areas of the border because there is not enough manpower there to capture them.

Wallace didn't seem convinced, but turned the conversation to constitutional questions concerning the national emergency, repeatedly pressing Miller on whether he can "name one case where a president has asked Congress for money, Congress has refused, and the president has then evoked national policy to get the money anyway?"

Miller refused to give Wallace the yes or no answer he sought, instead arguing the National Emergencies Act is Congress "saying the president could have this authority," so any time the president declares an emergency he automatically has congressional approval to spend money on the situation as he pleases.

Watch the full interview below, or read the transcript here. Bonnie Kristian