David Jackson

USA TODAY

Late in the election, Donald Trump got a lifeline courtesy of the FBI.

Friday's stunning announcement that FBI agents are reviewing new information about Hillary Clinton's private email use has emboldened Trump and aides who say the Nov. 8 election should be about the character of the Democratic nominee.

"We have one ultimate check on Hillary’s corruption, and that is the power of the vote," Trump told supporters Sunday at a rally in Las Vegas.

The New York businessman also claimed momentum has shifted in his favor, tweeting that "we are now leading in many polls, and many of these were taken before the criminal investigation announcement on Friday — great in states!"

The FBI did not announce a "criminal investigation" — and most polls still give Clinton a lead — but FBI Director James Comey's letter to congressional leaders about a review of new information has roiled the election in ways that campaigns, pollsters, and analysts are still trying to assess.

Republican consultant Bruce Haynes, founding partner of Washington-based Purple Strategies, said the FBI "bombshell" potentially "reframes the election as a referendum on Clinton and all the baggage she brings into office with her."

Clinton and her aides, meanwhile, raised a fairness issue, stressing that Comey did not specify what his agents are looking at, and issued only a vague statement on a Friday afternoon just 11 days before an election.

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Campaign chairman John Podesta, speaking on CNN's State of the Union, said his team doesn't know what new documents Comey is talking about, and "he at least ought it would explain if he think they're significant or not significant ... Let him come forward and say why."

Trump reveled in the news throughout the weekend, telling supporters it underscores his claims of Clinton "corruption," ranging from the ex-secretary of State's handling of classified information to claims of "pay to play" involving the Clinton Foundation and her State Department.

During his rally in Las Vegas, Trump pointed out that the FBI announcement stemmed from another investigation, this one into allegations that former U.S. representative Anthony Weiner sexted a 15-year-old girl. Weiner is the estranged husband of top Clinton aide Huma Abedin; the couple are now separated

"We never thought we were going to say thank you to Anthony Weiner," Trump told backers.

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Associates of the Republican nominee said the FBI news also speaks to doubts that voters have about Clinton.

"Frankly, I think they've also come to the conclusion that Hillary Clinton is a risky choice to be the next president of the United States," Trump running mate Mike Pence said on NBC's Meet The Press.

In July, Comey announced that the bureau would not pursue charges against Clinton and that the FBI found no evidence of intentional mishandling of classified information. Trump and other Republicans criticized Comey for that decision.

Speaking to supporters Saturday, Clinton said Comey now owes an explanation about his October letter to Congress: “It is pretty strange — it’s pretty strange — to put something like that out with such little information right before an election," she said. "In fact, it is not just strange: It is unprecedented and deeply troubling.”

Podesta told reporters: "Just to recap and put this in perspective, there’s no evidence of wrongdoing, no charge of wrongdoing, no indication that this is even about Hillary."

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The Republican team sees the FBI news as a potential turning point in a race that seemed to be slipping away from Trump just a few days ago. A series of polls last week gave Clinton solid leads over Trump, both nationally and in battleground states he needs to win in order to amass the 270 electoral votes needed for victory.

Polls over the weekend — including ones with questions asked before the FBI announcement — showed a tighter race, including in such pivotal states as North Carolina and Florida.

Texas-based political consultant Matt Mackowiak said continued news stories about Clinton will benefit Trump and Republican congressional candidates. Mackowiak said Clinton probably remains the favorite — she "has a better path to 270 electoral votes" — but "there is much greater uncertainty and volatility today than there was Friday morning."

Democrats, meanwhile, sought to rally their voters in light of the new developments.

The Campaign for America’s Future/Institute For America's Future, which describes itself as "the strategy center for the progressive movement," told backers in a fundraising e-mail Sunday that Trump "has closed the gap with Hillary Clinton," and the "trend goes one place, and it’s not good."

Urging supporters to get themselves and others to the polls, the e-mail said that "this election will be won on the ground."

Patrick Murray, director of the Monmouth University Polling Institute, said early polling since Friday reflects "a slight dent" in Clinton's lead nationally, but it's not clear if it will shift results in states that generate electoral votes.

A loss of Clinton votes could help Republicans in congressional races and other downballot contests, Murray said. He suggested looking at Republican-leaning "red states" where Trump is under-performing relative to other Republicans.

"The news has energized his supporters and it could help GOP candidates in tight Senate and House races in states such as Indiana and Missouri," Murray said.

Nicole Hemmer, an assistant professor in presidential studies at the University of Virginia's Miller Center, said Comey's letter is so vague that Trump and his aides can read anything they want into it.

"Will it have any effect on the ultimate outcome of the election?" she said. "Hard to say. But it will put Trump in a good mood for the next several days."