The liberal leftists ― the cultural Marxists ― very often invoke the so called “Slippery Slope” logical argument, as follows:

Slippery slope argument

This argument states that should one event occur, so will other harmful events. There is no proof made that the harmful events are caused by the first event. For example:

“If we legalize marijuana, then more people would start to take crack and heroin, and we’d have to legalize those too. Before long we’d have a nation full of drug-addicts on welfare. Therefore we cannot legalize marijuana.”

The same argument is used in relation to same-sex “marriage”: in case gay “marriage” is legalized, they say, it does not necessarily mean that either poliamory or polygamy would be legalized in the future. Or even it does not mean that our children’s sexual age of consent would be lowered.

The argument above is both nonscientific and fallacious (anti logical) itself, because a) it is proven that marijuana leads to hard drugs consumption, and b) you cannot morally sustain a legal prohibition when you’ve started making concessions on matters of principles concerning similar or even identical issues.

The greatest danger from the leftists’ agenda is that they use the systematic lie as the only mean of political action. Their ethics are teleological ― all means are previously justified to achieve their goals, including transforming the “Slippery slope” argument aforementioned in a slippery slope itself.