I know history bud, want to get into some detail? For every one big name movement like you are talking about I can name 10 (probably 100+ if I had to) examples of the US government beginning to encroach on new areas to interfere with.
The fact that you mention labor as some sort of success shows that you buy into the common narrative and haven't really looked at the situation. The 2002 study by Vedder and Galloway put the damage to the economy over the previous 50 years at $50 trillion dollars by unionism. Unions increase wages where they can restrict entry or have special privilege to intimidate employers but help to reduce wages overall.
Libertarians aren't actually opposed to unions if all a union is doing is organizing to protect rights of workers, but that isn't in truth how they operate. You can find more details on the study I mention and many more reasons why unionism is destructive here: http://mises.org/daily/1685
The US government is also the worst polluter on Earth, yet somehow you believe it has accomplished some triumph of environmentalism?: http://ivn.us/2012/04/18/the-number-one-worst-polluter-on-ea...
The government fails in its own task of enforcement in notable cases like the BP oil spill. There was legislation before this spill limiting liability for accidents like this. I think this was then sidestepped because of the severity of this spill, but it is an example of legislation actually protecting corporate interests and aiding their ability to pollute. When companies pollute, more often they end up paying a fine to the government rather than compensating victims. The common law mechanism whereby people can sell off their claim to a tort, no matter how minor, has been destroyed in modern, authoritarian systems.
The US government makes illegitimate claims to large areas of land and then takes money for leases on mineral/timber/other rights. This temporary ownership creates an incentive problem. When a company has no long-term stake, the tendency is to strip mine or clear cut a forest. Where instead a system of ownership is upheld, you see a tendency to have more sustainable treatment of land because there is a stake in the long term value of the property.
The same sort of structural incentive problem exists for democracy in general vis a vis systems like feudal monarchies (which, note, I do not advocate still either). When a king permanently "owns" his territory, there will often be some restraint in over-taxation or overly aggressive military adventures because the king is interested in passing on the kingdom to his heirs. In a democracy, temporary rulers have the incentive to make use of their power and "get in while the gettin's good".
The Iraq War may have been popular when Bush started the new salvo but this was based on false information crafted by this administration in order to plunge them into war. It's a problem that the system you advocate even puts a person in the position to manufacture terror like this. Public sentiment was at 2/3rds+ since at least 2006 against the Iraq War and the pullout could have happened swiftly long ago. The idea that these politicians are basing military policy on public opinion is ludicrous. You are clearly totally blinded by your worship of democracy. BTW, there are still at least 20-25K military and contractors in Iraq.
Look at the history of opinion on Afghanistan: http://www.gallup.com/poll/116233/afghanistan.aspx
That's 65-82% opposed every year except the dip to 54% in '05. I guess in your world of doublethink, this would be an example of democracy accomplishing the "pleasing of the most number of citizens".
Elections are mere popularity contests. These politicians do not represent you in the same way I would represent you if you handed me $5 and sent me to the store to get something specific. At times, politicians will react to public opinion or there are very slow movements towards ending their criminal policies like the Drug War. If pot was legalized at the federal level, would you add this to your list of great accomplishments? I'd list it as a failure due to the years of unjust policy previously, the millions of captives kept for victimless crimes now, the families and neighborhoods which would still be destroyed by the prohibition on other drugs.
Your statist ideology is outmoded. Information now flows more freely and the crimes of states will be laid bare. Once the "great western democracies" fully implode, people will question these types of systems and look for new solutions. That is what we are building now with things like blockchain-based tech, libertarian legal scholarship, etc.