The decline in Clinton's numbers lies partly due to Trump, partly to Sanders, but mostly to the fact that she's flat and uninspiring and temperamentally insincere. Her numbers will reverse and stabilize, as will Trump's, but in the context of late-summer empty speculation, it at least provides an opportunity to look both at the Democrats' bench, and how heavily the party establishment had already committed to Hillary's success. Notably absent from that is any sort of endorsement from the leaders of the current administration, the junior member of which had a weekend pow-wow with Elizabeth Warren.
Weirdness is afoot for the time being, but again, all that will shake out in the months to come. But what bodes for the party in the years to come? As the GOP becomes more and more unhinged and marginalized, a truly enterprising political party might see this as an opportunity to decouple from the ratchet-pawl pelf-grab the system has become.
Knowing the obscene amounts of money spent on this circus is one thing, knowing where it goes is another. Advertising through the same media that needs a horse race to keep the rates high is the primary use of the money; the industry of peckerhead pollsters and consultants is another. These folks get paid regardless of the outcome. In the meantime, more profit is generated by keeping it close, by inflating buffoons and downplaying contenders.
Hillary has an ace-in-the-hole that no other candidate from either party has -- Bill Clinton, easily the most charismatic politician since JFK, whose stature inexplicably wasn't even diminished by his signing the repeal of Glass-Steagall. The man is politically bulletproof, and can still convince people like the best televangelists only dream of. Once the real season gets underway, Hillary doesn't need to say much of anything -- she just needs to pull the Big Dog out of whoever he's balls-deep in that week, and put him at the podium.
In a political season where "populism" and "antiestablishment" sentiments are supposedly the driving factors, you just watch how soon the tide will predictably turn right back to tedious incrementalism. I hold out hope for Sanders, but also realize that the "left" in this country is really just a bunch of yuppie suburban assholes who would sell their children's economic prospects down the river just for the false promise of selecting a couple of SCOTUS occupants who might hold the line for the right to get an abortion (which has been severely curtailed throughout the country with or without the Supreme Court). They'll turn on Sanders the very second they can find an excuse to exhume the sad bones of Ralph Nader.
Just as the movement to curtail reproductive rights cannot survive without the involvement of misguided women, neither can you end up with a "liberal" party that does very little for true economic and social justice, without the bien pensant meddling of former idealists who play just not to lose, and have lost whatever compelling vision they thought they had when they were dropping acid and blowing Jerry Garcia at Woodstock. The only thing worse than someone who sells out is someone who refuses to admit the obvious.