Yes, in an ideal world congress should or would appropriate funds.
However, we are no longer in an ideal world and this attitude was nowhere to be found under the last President so this is one of those “hold your nose votes” the left makes with no problem or qualms.
They fight with everything they have and we don’t. It seems inevitable that the republicrats will one day sit in the losers bracket patting themselves on the back that “at least we did it right.” Sigh.
While he has a point in principle the constitution is very clear to me that border control is a matter of national defense so there have been many other “emergency declarations” on far shakier ground than this one.
At least declaring this law Unconstitutional would mean no President could declare a national emergency. The Democrats, being duplicitous as usual, want to stop President Trump while allowing their Presidents to have this power.