First off, .....
.....first off, you have no fricken clue as to the specifics of why violent crime is plummeting. You spout some #'s and immediately make that the only applicable variable. The lower crime rate can JUST as easily be connected to more firearms in responsible law abiding hands. That can also be reinforced by the fact that those areas with stricter gun controls, that make it far more difficult for the law abiding to own/carry a firearm, have seen their crime rates rise, despite it plummeting nationally. Point being, you rhetorically shot your own foot off, when you yourself highlighted the plummeting violent crime #'s despite a proliferation of legal gun onwership
The slogan Make American Great Again assumes that America has lost its greatness.
And when you ask a majority of Americans.....THEY'LL AGREE. Our country has had many eras of greatness, the latter years of Reagan & the early years of Clinton, were pretty stellar. Our contributions to ending WWII were pretty stellar. Our bringing the end to legalized slavery was pretty stellar. In all those eras, anyone can fine things that weren't "so stellar", the Civil War inparticular, where we lost more American lives to war, than any other war, before or after. But that was a necessary war, that included much loss of life, but wasn't terrorist-centric in any way
So NO, it does not require a specific date, because as you've helped demonstrate, any era of greatness, is going to have some negatives. And while I have no idea as to what specific policies Trump might bring to the table to help out ALL Americans, not just the middle class, what we ALL do know, is that the current policies of the left, are decimating the middle class