'is possible of' is not correct or usable in written English.
The correct version of this phrase should be 'is possible.' For example: It is possible that the answer to this question is unknown.
It is possible, of course, that both views are true.
It is possible, of course, that this was mere storytelling.
It is possible, of course, to get killed anywhere in Chechnya.
It is possible, of course, to read Bush v. Gore more narrowly than that.
It is possible, of course, that China's approach to foreign policy can shift again.
It is possible, of course, for media attention to galvanize action.
It is possible, of course, that Tehran will refuse this diplomatic presence.
It is possible, of course, to sympathise with the position du Plessis found himself in.
I believe I've gone to the limits of what is possible, of my responsibility.
It is possible, of course, that this latter argument will turn out to possess substance.
It is possible, of course, that she was just being plain rude.
