Democratic operatives told the Washington Examiner on Saturday that it's unclear that Hillary Clinton or any of the myriad groups supporting her candidacy planted the sharpest attacks Donald Trump has absorbed in the past week.

"It's hard to tell exactly where this came from," Rodell Mollineau, who was a founder of American Bridge, a Democratic super PAC that focuses on opposition research, said, referring to the video of Trump bragging about groping women and trying to woo a married woman.

It makes sense for the Democratic nominee and her allies to unleash their choicest opposition research hits now, just as early and absentee voting accelerates in electoral battlegrounds, for maximum impact. But this might not be their handiwork, meaning Trump has even more to worry about.

"This is not a conventional campaign. There are a lot of people with long knives out for Donald Trump that don't want to see him president," explained Mollineau, now a partner in the bipartisan consulting firm ROKK Solutions. "I wouldn't start and end with this either being the Clinton campaign or the super PAC that did this."

The Republican nominee was still reeling from a leaked video of him making lewd comments about women 11 years ago.

On Friday, the Washington Post reported on a video of Trump from 2005 discussing his exploits with women with television personality Billy Bush. Trump, a real estate developer, was 59 years old at the time and the middle of his successful run as the host of "The Apprentice," a reality television show.

The conversation, caught on a hot microphone, revealed Trump using explicit language as he talked about women's physical attributes and how being a television star made it acceptable for him to make unwanted sexual advances. But that's only the second instance of opposition research Trump has endured in the last week.

On Oct. 1, the New York Times published an expose on Trump's 1995 tax returns that showed that the GOP nominee reported a nearly $1 billion loss that year and might have used that filing to legally avoid paying income taxes for the next 18 years. The Clinton campaign said Tuesday that it did not plant this story.

It's still unclear if the Clinton campaign was in any way behind the leak of the lewd Trump video from 2005. But to underscore that Trump might have more enemies to worry about than his Democratic opponent and her allied political groups, a former producer of "The Apprentice" tweeted this Saturday evening:

"As a producer on seasons 1 & 2 of #theapprentice I assure you: when it comes to the #trumptapes there are far worse #justthebeginning," Bill Pruitt tweeted.

Trump has experienced his share of missteps and cringe-worthy moments as a presidential candidate.

But the scandal surrounding the video of his lewd comments about women, dubbed "#trumptapes" on Twitter, caused several Republican elected officials to condemn Trump in harsh terms and take the unusual step of rescinding their endorsement.

Trump, who is vowing to stay in the race, is scheduled to debate Clinton for the second time Sunday evening.

Producing useful opposition research is costly, time consuming and painstaking. The political operatives that do the work don't necessarily know what they're looking for and often have to dig by hand through reams of public records to uncover information that might or might not be worth packaging as a political attack.

General election campaigns usually begin stockpiling opposition research more than a year before Election Day, as long as they have an idea of the possible candidates. But whether the information ever becomes "weaponized" depends on how the unpredictability of the campaign unfolds.

Clinton's attack on Trump over demeaning comments he made to Miss Universe contestant Alicia Machado are an example of the kind of planned, campaign-driven opposition research the Republican can expect to see more of over the next couple of weeks.

Clinton delivered the hit during the first presidential debate. But it wasn't by chance.

The very next day, her operation was ready to go with a campaign video and a conference call featuring Machado to discuss her experience with Trump. And it worked in large part because female voters have a low opinion of Trump. It might not have worked otherwise.

Clinton could have more in store for Trump in Sunday's debate, although the town-hall style format is a trickier setting for launching attacks.

"The real opposition research triumph of last month is the Machado thing," said Matt Gorman, who was the rapid response director for Republican presidential candidate Jeb Bush. "That was something that was kind of textbook oppo."