Easiest way to get a good argument going on FR is to ask "When did America change for the worse?".
IMO, it was Kennedy's assassination.
But, equally learned - or more learned - FReepers have cogently argued that it was when BO was elected. Or Bush. Or the Twin Towers. Or Clinton. Or the Hippie / Vietnam era. Or "1861 / 1865". Or it ended with FDR and the New Deal.
My far too labored point is that even with the advantage of history and hindsight, such things aren't obvious. :-)
No doubt this was a good week. The Dems advance was stopped in 2010, the Republicans fumbled in 2012, but we just got the ball back. Hopefully, we'll move it to midfield where it belongs.
Really hard to say when the decline began this time. We have had others but I think none so sour as this one. Kennedy paved the way for LBJ and so yes, probably. Social Security and the New Deal alone are probably not sufficient alone to the fall. Wilson and the 16th and 17th amendments certainly planted seeds and laid the foundation for loss of states rights and personal freedom. The payroll deduction of the Roosevelt era covered up the real cost of government from the sheeple. The application / misapplication of the 14th has to be about the stupidest thing we have ever sat by and allowed.... so we have probably been busy destroying the founding principles for 150 years. The last 50 and the last 6 of that have kicked it all off the cliff.