There are moments in this extraordinary American campaign for president when the information moves so fast, the revelations are so distressing, the rhetoric is so heinous and the tone and tenor so dystopian that it doesn't feel real.

And just as the two most unpopular party nominees in modern history barrel toward the final stretch – a period customarily animated by hope, idealism and exceptionalism – it's plunged further into the depths of the gutter.

Instead of lofty talk about the future of the shining city upon a hill from two opposing governing perspectives, it's all about sex, lies and videotape.

Under siege from all sides and digging in, Donald Trump is framing the election as a struggle for the nation's survival against an opponent that should be in jail. Hillary Clinton says matter-of-factly that she's "the last thing standing between you and the apocalypse."

This campaign has long been more about fear and distrust than hope and change, but the roiling series of events over the last week have jolted the system in ways not experienced in modern political times.

"Maybe in some banana republic somewhere," observes longtime GOP operative Charlie Black, "but there's been nothing like this here."

After a 2005 tape emerged showing Trump describing in vulgar terms how he could force himself on women and grope them simply because of his celebrity status, the former star of "The Apprentice" dismissed the embarrassment as "locker room talk."

Some political pros now suspect the tape was laid out like bait in a trap, daring the accused to deny. And deny he did, marking – extraordinarily – the first time a candidate for president has been forced to say he's not a sexual predator in a televised debate.

Then came the women, almost all at once, in a dizzying swoop that put names, faces and detailed allegations behind a troubling storyline.

The People Magazine reporter who said Trump pushed her against a wall and forced his tongue down her throat. The paper company businesswoman who said Trump groped her breasts and tried to put his hands up her skirt during a flight. A real estate receptionist who recalled that when Trump shook her hand, he refused to let go and then kissed her mouth. The photography assistant who alleged Trump grabbed her buttocks at his Mar-a-Lago estate. On Friday, another woman emerged, telling The Washington Post Trump slid his fingers up her skirt inside a Manhattan nightspot in the early 1990s.

Trump has vigorously refuted it all, raising in his usual dramatic and highfalutin fashion the prospect of a grand conspiracy against him. Among his most devout followers, this will only reinforce the notion that the fix is in.

"You've already got Donald Trump questioning the election's legitimacy," Democratic pollster Mark Mellman notes. "We live in a country where 30 to 40 percent of Americans could believe an election is not legitimate, if he says it enough. We've never seen that before. There's never been a question before. But Trump is sowing the seeds of that potential."

But as Trump worked his fans into a lather against a "dishonest" media and a "rigged" system, first lady Michelle Obama stood soberly and sadly on a stage to convey that this was no longer about run-of-the-mill, rough-and-tumble politics.

"It has shaken me to my core," she confessed at a Clinton rally in New Hampshire, referring to Trump's comments on the 2005 tape. "It's not something we can just sweep under the rug as just another disturbing footnote in a sad election season."

"This is not normal. This is not politics as usual," she said.

Clinton noticeably has attempted to detach herself from the ugliness, preferring to let Trump self-immolate all on his own. She was off the trail Thursday and Friday, dutifully raising money in private gatherings and then heading into preparation over the weekend for the final debate set for Wednesday night in, appropriately enough, Sin City.

She has been through the sleaze machine many times before and bears the scars to show there is no advantage to diving back in, especially when she's winning and expects to govern a damaged country in just a few short months.

"She may think she's in good enough shape to hold the ball and kill the clock," Black says. "She doesn't see any reason to be out there speaking every day, especially when you've got [President Barack] Obama and Michelle [Obama] leading the news. Why step on that? Every time she's out there, people are reminded what they don't like."

Besides, early voting is already underway, and the Clinton campaign believes outcomes in Florida, Nevada and North Carolina could be determined before Election Day. If Trump drops any one of those three, he has virtually no path to the presidency.

The Clinton camp also is forecasting the biggest turnout in history. In Florida, more than 2.8 million voters have requested absentee ballots, up from 2.1 million at this point in 2012, according to a Clinton aide.

In North Carolina, voter registrations among Hispanics are up 49 percent and Democrats are returning their absentee ballots at a slightly higher rate than Republicans, Bloomberg reports .

And yet, with 25 days left, the Clinton campaign is still unnerved that all the continued venom could turn people off and keep them from participating.

John Podesta, Clinton's campaign chairman, said this week that Trump's strategy is to "disgust everyone with our democratic dialogue so that they won't come out to the polls."

But Elaine Kamarck, a senior fellow in the governance studies program at The Brookings Institution and veteran member of the Democratic National Committee, believes the more bombs Trump throws in his waning days as a candidate, the higher turnout will soar, especially among the country's majority gender.