Well if he was born in kenya, what doesn’t matter is any law he signs, any command he gives, any appointment he makes...nothing.
Why are they really worried? Because if he is not a natural born citizen, then the US military would be compelled to remove him and his buddies from office. Also his campaign was fraudulent and he deceived the voters so the election would be invalidated. They fear the constitutional crises that will follow. If this happens we could witness the greatest shift back to states rights since Abe was President.