-    Under constitutional freedom of contract, whatever either party has the right to treat as sufficient ground for terminating the employment, where there is no stipulation on the subject, ,he has the right to provide against by insisting that a stipulation respecting it shall be a sine qua non of he inception of the employment, or of its continuance if it be terminable at will
-    An interference with this liberty so serious as that no under consideration, and so disturbing of equality of right, must be deemed arbitrary, unless it be supportable as a reasonable exercise of the police power of the state. To as a man to agree, in advance, to refrain from affiliation with the union while retaining a certain position of employment, is not to ask him to give up any part of his constitutional freedom. He is free to decline the employment on those terms, just as the employer may decline to offer employment on any other for it “takes two to make a bargain.”