Yes, its true... Trump's popularity is under water. However, that doesn't mean we should feel happy or comfortable about the situation.
After years of scandal after scandal, after a Mueller report that pointed out evidence of various crimes, and after the most recent rape accusation, his popularity is not only stable but GOING UP. (Assuming its not just some statistical error.) And there is nothing I can think of that might justify the increase... no big legislation that he managed to help pass through congress, no big international problem he's helped to address. The only thing that i can think of is maybe the Iranian situation, but its hard to see how "I was going to bomb them but decided not to" would really affect his popularity.
That doesn't give much leeway for the democrats. Pick the wrong candidate, or have some unexpected November surprise, and Trump may still pull off a victory.
I want to see Trump lose, and not just by a few percentage points... I want to see him utterly humiliated, and I want to see the entire republican party dragged down with him, followed by at least a decade of them being shut out from any hint of power, as a warning to them that picking a racist con-artist as your leader and engaging in underhanded shenanigans can lead to ruin.
Well given the fact that a waltz is a form of physical activity, I can't see Trump waltzing anywhere (unless he can figure out how to do it while driving a golf cart).
Seriously, I think you're getting hung up on the phrasing here. Yes, "waltzing to victory" implies an easy win, but I think the term could apply to to the 2016 election... Trump's campaign was often labeled a "dumpster fire", but he still managed to pull off a victory, despite not putting any effort into coming up with decent policies or making any serious attempts to appeal to voters outside of his base.