I'm aware that 'if not' can be used to mean 'perhaps even' as in 'million if not billions of people...' I was wondering if the use of 'if...not...' was something along those lines in the below?
People who believe this readily accept that 'socialism' in a mild social democratic version, remains, and will long continue to be, part of the political scene of capitalist societies, and that it may even become, if it is not already, a stronger current of thought than laissez-faire capitalism.
So what I initially read was: Social democracy seems rampant enough at the moment & it is already kind of a stronger current of thought & if there are any uncertainties about this claim, there won't be in the future.
Or does it mean: Even though social democracy is not really a stronger current of thought nowadays...it will certainly become so in the future??