Hence the “controlled” part. The intention of controlled opposition is to play to liberal sensibilities without actually being opposition (also, the two parties sometimes differ as to which portion of the bourgeoisie class they represent, though the venn diagram of their actual constituency is nearly a circle)
They’re not even opposition, just the other side of the same coin as Republicans.
Hence the “controlled” part. The intention of controlled opposition is to play to liberal sensibilities without actually being opposition (also, the two parties sometimes differ as to which portion of the bourgeoisie class they represent, though the venn diagram of their actual constituency is nearly a circle)