The country’s top intelligence official testified to Congress on Thursday that Russia’s meddling in the 2016 presidential campaign went well beyond hacking to ­include disinformation and the dissemination of “fake news” — an effort, he said, that continues.

“Whatever crack, fissure, they could find in our tapestry . . . they would exploit it,” said Director of National Intelligence James R. Clapper Jr., testifying before the Senate Armed Services Committee on foreign cybersecurity threats, especially Russian hacking and interference in the election.

The hearing brought one of the most contentious post-election ­issues directly to Capitol Hill and to a national audience. Predictable partisan political lines were drawn. Most Republicans seemed disinclined to address head-on the intelligence community’s allegations of Russian hacking and used the hearing to criticize President Obama’s handling of the cyberattacks.

But Democrats and the leading Republicans on the committee — Sens. John McCain (R-Ariz.) and Lindsey O. Graham (R-S.C.) — eagerly questioned intelligence officials about Russian interference in the election and seemed ready to embrace their conclusions about the Kremlin’s motives.

Trump has repeatedly voiced skepticism about the intelligence community’s conclusion that Russia interfered to help him win the White House.

Sen. Claire McCaskill (D-Mo.) on Thursday took a swipe at Trump. “Who benefits from a president-elect trashing the intelligence community?” she said, adding, “Who actually is the benefactor?”

Clapper replied that “there is an important distinction here between healthy skepticism, which policymakers, to include policymaker number one, should always have for intelligence, but I think there is a difference between skepticism and disparagement.’’

Former CIA director R. James Woolsey Jr., a veteran of four presidential administrations, resigned Thursday from Trump’s transition team because of growing tensions over Trump’s vision for intelligence agencies.

Woolsey’s resignation as a Trump senior adviser comes amid frustrations over the incoming administration’s national security plans and Trump’s public comments undermining the intelligence community.

“Effective immediately, Ambassador Woolsey is no longer a Senior Advisor to President-Elect Trump or the Transition,” Jonathan Franks, a spokesman for Woolsey, said in a statement. “He wishes the President-Elect and his Administration great success in their time in office.”

People close to Woolsey said that he had been excluded in recent weeks from discussions on intelligence matters with Trump and retired Lt. Gen. Michael T. Flynn, the incoming White House national security adviser. They said Woolsey had grown increasingly uncomfortable lending his name and credibility to the transition team without being consulted. Woolsey was taken aback by this week’s reports that Trump is considering revamping the country’s intelligence framework, said these people, who spoke on the condition of anonymity to comment candidly.

At the hearing, Sen. Tom Cotton (R-Ark.) and others cast doubt on the idea that Russia would want to help Trump.

“Donald Trump has proposed to increase our defense budget, to accelerate nuclear modernization, to accelerate ballistic missile defenses, and to expand and accelerate oil and gas production, which would obviously harm Russia’s economy,” Cotton said. “Hillary Clinton opposed or at least was not as enthusiastic about all those measures.”

But McCain and Graham, two longtime national security hawks, were adamant that more needs to be done to punish and deter Russia.

In the most dramatic portion of the hearing, Graham asked Clapper whether he was ready to be challenged by Trump, and Clapper said he was. Graham also advised Trump, “Mr. President-elect, when you listen to these people, you can be skeptical, but understand they’re the best among us and they’re trying to protect us.”

Graham criticized Obama’s response to the election-year interference, which included imposing economic sanctions on top Russian spy agencies and officials and expelling 35 Russian “intelligence operatives.”

“What Obama did was throw a pebble,” he said. “I’m ready to throw a rock.”

Graham did not specify what form of punishment he would like to see, though he and McCain, the Armed Services Committee’s chairman, have said in recent days that they want to impose stronger sanctions on Russia.

At the hearing, Clapper said the intelligence community stands “more resolutely” than ever behind its assessment — first publicly announced on Oct. 7 — officially accusing the Kremlin’s “senior-most” officials of orchestrating a campaign of interference in the 2016 election.

More details on Moscow’s array of influence operations will be included in a report briefed to Congress next week, Clapper said. A declassified version will be made public.

Clapper noted that while much of the public focus over the past six months has been on Russian hacking of Democratic Party organizations, the Russian campaign of fake news, often promoted on social media, should not be overlooked. He pointed to Russia Today, also known as RT, a ­Russian-government-funded international television network that Clapper said is pushing a point of view “disparaging our system, our alleged hypocrisy about human rights.” Whether it was RT, “use of social media, fake news,” he said, “they exercised all of those capabilities in addition to the hacking.”

Sen. Tim Kaine (D-Va.), who was Clinton’s running mate, said he was the subject of several fake news stories. The mainstream media ignored them, he said, “but one of the stories was shared 800,000 times.” Some originated within the United States.

He then took a jab at Trump’s pick for national security adviser, Flynn, a former military intelligence officer who has drawn criticism from some former colleagues for his strident support of Trump. Without mentioning Flynn’s name, Kaine alluded to Flynn sharing on Twitter a baseless story claiming that members of Clinton’s campaign were engaged in a child prostitution ring. Flynn, who has not responded to questions about the story, has since deleted the tweet. Still, Kaine decried “an administration that has put in place as the proposed national security adviser someone who traffics in these fake news stories and retweets them and shares them . . . stories that most fourth-graders would find incredible.”

Clapper said that to counter Russian propaganda, the United States should undertake a more aggressive counter-propaganda effort, something akin to a beefed-up U.S. Information Agency, which was dissolved in 1999.

Asked why that has not yet happened, National Security Agency Director Michael S. Rogers, who also testified Thursday, said, “I don’t think we’ve come yet to a full recognition of the idea that we’re going to have to try to do something fundamentally different.”

Added Rogers, who is also head of U.S. Cyber Command, “I think we still continue to try to do some of the same traditional things we’ve done, and expecting to do the same thing over and over again yet achieve a different result.”

Earlier this week, Trump praised Julian Assange, co-founder of WikiLeaks, the transparency group that has been criticized by the Obama administration for damaging national security leaks. Trump has indicated that he believes Assange’s comments that Russia is not behind the Democratic Party hacks, placing him at odds with the intelligence establishment. Trump on Thursday, though, said his comments on Assange had been misunderstood.

When asked by McCain whether “any credibility” should be attached to Assange’s comments, Clapper responded, “Not in my view.”

He later added, “I don’t think those of us in the intelligence community have a whole lot of respect for him.”

McCain, who has been critical of the Obama administration’s responses to cyber-provocations by foreign nations such as China and Russia, pressed Clapper on whether the campaign meddling was an attack on the United States and an “act of war.”

“We have no way of gauging the impact — certainly the intelligence community can’t gauge the impact — it had on choices the electorate made,” Clapper replied.

Determining whether an action is an act of war is a “very heavy policy call that I don’t believe the intelligence community should make, but it certainly would carry, in my view, great gravity,” Clapper said.

(Bastien Inzaurralde/The Washington Post)

Sean Sullivan contributed to this report.