On the point of constitutionality, the US has banned immigration on similar grounds before many times. We banned Chinese coal workers for fear that they were stealing American jobs. We banned Jewish refugees (Judaism is a religion btw) from Germany during WWII. We've even banned Iranians before during the hostage crisis in the 70's. In all of these cases the constitutionality held. The 9th would be overturning quite the precedent in ruling this unconstitutional.
That's why I mentioned the liberals seem to be on the wrong side of history on this one.
Do you really think those above examples are the "right" side of history? Has history vindicated the US for turning away Jewish refugees from Nazi Germany??