These national emergencies have been in the foreign policy arena and none of them directly contradict the Constitution. The Congress cannot give a President the powers that are delegated to Congress by the Constitution such as the power of the purse. They did not give him the power to as Justin Amish tweeted, "No.
@POTUS can’t claim emergency powers for non-emergency actions whenever Congress doesn’t legislate the way he wants."
Just because he cannot get money from Congress for a wall does not make it a national emergency to do a end run around Congress. Just because you want something does not mean a compromise has to include it. Around a year ago when Democrats wanted DACA as part of a compromise bill, Republicans refused to include DACA in a compromise. Gridlock is not a justification for using a national emergency to do a end-run around Congress. If you could, Obama could have declared a national emergency to go around a Republican Congress.
Regardless of what you or Justin Amish think a national emergency should be, under the National Emergencies Act a national emergency is anything the President says it is, and neither Congress nor the Courts have jurisdiction over what constitutes a national emergency, and since the law gives the President 123 extraordinary powers under a national emergency to use the funds in the DoD military construction budget ($10.5 billion, mostly now designated for military housing) to build the smart fence, there are no legitimate legal grounds on which to challenge him. There are only two ways to prevent the President from securing our southern border under a declaration of national emergency, rally 2/3 of each house of Congress to overturn the National Emergencies Act, or impeach and convict the President. Of course, both will fail.
Barack Obama declared 13 states of emergency in order to gain extraordinary powers and not one of them dealt with a threat to American people or American property; all of them dealt with seizing the property of or blocking commerce with people who were party to foreign conflicts in which the US was not involved. None of these issues was so time sensitive that he couldn't have gone to Congress to seek their approval, but given his poor relations with Congress, he probably would have had to undergo the same kind of obstruction by Congress on each of the EO's issued under these national (non)emergencies.