The Left/Democrats don't really have an issue with the past sins of the U.S. After all, the most egregious sins of the U.S. were committed by the Democrats themselves. These sins were: slavery; fighting to keep it; Jim Crow laws; fighting against civil rights, etc. The Democrats right now are just systematically undercutting the moral authority of all aspects of the U.S., by citing its various sins, as grounds to push for changes that are advantageous to them. E.g. citing the separation of families at the border. This undercuts the moral authority of President Trump to stop illegal immigration, which furthers the Left’s interests - uncontrolled illegal immigration. Uncontrolled illegal immigration gives the Democrats an overwhelmingly majority of new voters, as well as their donors cheap labor.
The push for attention to climate change, is an attempt to cite the Left’s perceived excesses of U.S. consumerism, as moral grounds to implement increasing controls and regulations on society. Every act of pursuit of wealth generates carbon. If you build businesses and industry, this generates carbon, and the Left as a consequence, push for regulations which slow this down to a halt. (Why do they do this? Environmentalists hate human progress and growth! They believe it is bad for the planet, and with them, the planet comes first!)
Further, if you have a child, it produces a world of carbon, because you have to take the child to school, you have to buy things for the child (and these things that you buy, give off carbon when they are produced). When the child breathes, the child gives off carbon as well. Climate change ideology effectively condemns the U.S. capitalistic and familial ways of life, suggesting virtually every aspect of it is bad, and must be controlled by the government, if the U.S. and the rest of humanity is to be saved. Ultimately the Left is hoping to make climate change, its centerpiece construct to exert communist type control on the West.
So the Left bombards America with a host of accusations, meant to undermine the moral authority of Americans to pursue the American dream. The Left then uses its accusations to shred the American dream, with onerous regulations and control.
No one should think that the Left cares about morality. What the Left care's about is exploiting the ‘moral failings’ of the U.S., to push for their agenda - which rolls over the individual rights and aspirations of Americans.
Post was updated: 2/8/2019.