Political activists on the secular Left have a systemic problem. In order to remain Progressive they must constantly push all social and moral boundaries back and overturn whatever traditions they may encounter in their quest for perpetual change. Like early 19th century pioneers who, when they stopped moving westward, ceased to be pioneers and became settlers, Progressives must continually drive Leftward lest they cease to be Progressives and be absorbed into the status quo.
What this means in practice is that no achievement, no amount of change, can ever satisfy them. For example:
Once abortion on demand was securely entrenched as the law of the land, the Left turned its guns on preserving the right to have a partial birth abortion. Once the right to partial birth abortion is secured, the struggle will then focus on legalizing infanticide and euthanasia for the elderly.
Once prayer was removed from public schools the next step was to banish Christmas as well. As soon as that is accomplished the very mention of the word God will be proscribed from our schools, unless used as an imprecation or expletive, in which case it'll be okay.
Once obscene language restrictions were relaxed on television broadcasts then the struggle began to get them abolished altogether.
As soon as society began to show tolerance and acceptance for gays as people the movement to redefine marriage so that gays can marry was initiated. Once gays win the right to marry, prohibitions against polygamy and other forms of polyamory will come under assault.
As environmental pollution was reduced to minimal levels by legislation a push began to eliminate it altogether, regardless of the enormous cost and the relatively marginal benefits.
If people are paying 50% of their income in taxes Progressives insist they be required to pay 60%. Once the tax rates are raised to 60%, the Left will demand that they be raised to 70%. Likewise with the minimum wage.
If implied sexuality in movies has yielded to more explicit scenes, then the filmmaker should be free to make those scenes as sexually vivid as he wishes.
If the voting franchise is extended to all citizens, then it needs to be extended to non-citizens and illegal aliens as well.
If the voting franchise is lowered to age 18, then it should be lowered to age 16.
If 18 is the age of legal majority, then it should be lowered further so that sex with minors violates no laws.
If the U.S. defeats Iraq in a few weeks worth of combat, it's not to be considered a victory as long as there's looting and economic chaos. Once looting and disorder are placed under control there still is no success until there's an interim government. Once there's an interim government in place, the American effort is still not to regarded as successful until there democratic elections. But elections will be said to be meaningless as long as there's an active insurgency in the Sunni triangle.
The appetite for change is voracious and insatiable. The horizon is always receding. No achievement is ever sufficient. There is no goal or end-point to which we can strive. Once one objective is achieved the ultimate goal is pushed further back in a never-ending dystopic quest for the Progressive paradise. Government must grow ever larger and control ever more of our individual lives. Personal freedom, except insofar as it is freedom to indulge our appetites, must be hemmed in and constrained by a crushing mountain of rules, laws, and regulations.
The Left can never stop and say we've come far enough. Like locusts, they must keep devouring everything in their path, they must keep pressing on in search of new fields to ruin. Like bicyclists, to halt is to lose their balance. To stop is to lose their grip on the meaning of their existence. The animating force of the Left, at least the secular Left, is a neurotic impulse to destroy what has been built by others.
This is why so much of twentieth century Leftism devolved into nihilism, and it is why so many contemporary Leftists offer nothing constructive as solutions to the problems we face today. Their only answer is to tear down or wear away the principles, institutions, and beliefs of earlier generations.
George Santayana once said that "When change is absolute there remains no being to improve and no direction is set for possible improvement; and when experience is not retained, as among savages, infancy is perpetual." It is distressing that perpetual infancy is so appealing to so many in Europe and the U.S.