If you cannot predict future events with your theory--you don't have a theory--you have flappdoodle.
Again--what leftist predicted where we would be today economically (NOT IS-LM or AD-AS) but a person (in government) who predicted our current state... Who? When?
The scientific method is NOT vulnerable if the scientist is practicing science. If you have a theory--it is replicated by another lab--if it works to predict you have something. If it does not... you don't.
Its that simple and why Physicist don't have half the trouble with controversy as climatolgists, evolutionists, economists, or political scientists.