Federal authorities concluded months ago that as many as two email systems associated with the Republican National Committee had been attacked by Russian hackers, but those systems were so outdated and had remained unused for so long that neither RNC officials nor authorities became particularly concerned about it, several officials with knowledge of the matter told ABC News.
In fact, according to RNC spokesman Sean Spicer, the RNC hired a private cybersecurity firm to review the matter and determined that any compromise came through the personal computer of a former employee, who left the Republican institution several years ago but still had his old email account on the device.
That computer had not been connected to an RNC server in years, said Spicer, who noted there was consequently no way for RNC systems to be hacked.
By contrast, a successful cyberassault on the Democratic National Committee earlier this year led to an embarrassing online release of thousands of internal messages -- some so problematic that then-DNC chairwoman Debbie Wasserman Schultz ultimately resigned. Emails stolen from the private email account of Hillary Clinton's campaign manager, John Podesta, also led to a series of uncomfortable disclosures that were repeatedly highlighted by now-President-elect Donald Trump and other critics during the presidential campaign.
"The DNC [hack] was the crown jewels. The RNC not as much," said one official not aligned with Republicans but briefed on the matter.
Another official familiar with the matter said authorities "were never concerned with the RNC" in the same way they were distressed by the DNC hack because "the extent of the compromises were completely different," no Republican-related documents were being distributed "in the wild" and the RNC was fully cooperating with federal authorities.
The question of whether the RNC suffered a cyberbreach at the hands of Russian hackers became a central point of contention this past weekend, after news reports said parts of the U.S. intelligence community concluded Russian hackers targeted the U.S. election system in hopes of boosting Trump's bid for the White House.
Previously, U.S. officials had been saying any Russian interference in the U.S. election was solely intended to undermine the credibility of the entire Democratic process, not to favor one presidential candidate.
On Friday, The Washington Post first reported the CIA had concluded in a secret assessment that Russia intervened in the 2016 election to help Trump win the presidency. Then The New York Times added a new wrinkle: The CIA conclusion was based in part on the discovery that Russians had hacked the RNC's computer systems but did not leak any stolen information like they did with the DNC.
Over the next two days, RNC officials vehemently denied the New York Times report, insisting on various news shows that no RNC systems were compromised.
"The RNC was not hacked," outgoing RNC Chairman Reince Priebus told anchor George Stephanopoulos on ABC News' "This Week" Sunday morning. "We contacted the FBI months ago, when the DNC issue came about. They've reviewed all of our systems. ... And the conclusion was then, as it was again two days ago when we went back to the FBI to ask them about this, that the RNC was not hacked."
Nevertheless, the RNC and other Republican institutions were targeted by Russian hackers, sources said. But not all attempted hacks are created equal.
Targeting an outdated and dormant RNC system could be an attempt to look like Russians are bipartisan in their espionage when in fact they are targeting "something that doesn't matter" on the Republican side, one Democrat-aligned source said.
On "This Week" on Sunday, Priebus, who will be Trump's chief of staff in the White House, questioned whether Russian hackers were behind the DNC hack to begin with, insisting the U.S. intelligence community "didn't conclude it was Russia."
In fact, however, the Department of Homeland Security and the director of national intelligence, representing all 17 U.S. intelligence agencies, issued a rare public statement in October that began this way: "The U.S. Intelligence Community is confident that the Russian Government directed the recent compromises of emails from U.S. persons and institutions, including from U.S. political organizations."
"Frankly, I don't know a Democrat or Republican who has heard the intelligence that would quarrel with those conclusions," the top Democrat on the House Intelligence Committee, Rep. Adam Schiff, D-California, told NBC News on Sunday morning.
According to a U.S. official, intelligence agencies in recent weeks uncovered new information that "added a different layer" to the government's understanding of Russia's role in the hacking of U.S. political institutions, and it allowed intelligence agencies to make new "linkages" between the Russian government and the hackers who targeted those institutions.
These new developments were recently briefed to relevant lawmakers, the U.S. official said.
A Republican congressional aide downplayed the significance of Russian cyberattacks.
"Russia does this sort of thing everywhere in the world wherever they can," the aide said, speaking on the condition of anonymity. "I'm not sure how [anyone] can purport to know what their motivation was."
Citing Russia's role in the DNC hack, the aide suggested Russian President Vladimir Putin -- like "the rest of the world" -- may have thought Clinton was a lock to win the presidential election, so leaks of stolen emails related to her could have just been intended to embarrass her while in the White House.
But Schiff called such sentiments "simply not credible."
"You would have to believe that the uniform nature of the hacking and the dumping of information that was damaging to Secretary Clinton and helpful to Donald Trump was both coincidental and accidental, and the Russians didn't know what they were doing, to believe that they had no interest in helping one candidate," he said on NBC News.
A congressional staffer said disputes over what was behind Russia's cybercampaign ahead of the U.S. election and disagreements over exactly what was compromised are "really why we need a more fulsome investigation to get these facts out there."
The staffer praised the White House's recent announcement that the U.S. intelligence community would be conducting a wide-ranging and in-depth review of cyberattacks during the presidential campaign.
"These are the Russians, and they were wildly successful in affecting the outcome of an election. You need a 9/11-style commission for that," the staffer said.