The main U.S. stock indexes plunged on Monday, weighed down by negative news about Apple and Facebook.

Facebook shares fell by nearly 6 percent in continued fallout from a New York Times report on the social network's aggressive response to criticism over its handling of fake news and other efforts to influence public opinion. Apple shares fell by 5 percent after a Wall Street Journal report that disappointing sales had prompted the company to cut orders for its latest iPhones. Shares of Google-parent Alphabet also fell by 4 percent.

The Dow Jones Industrial Average closed down by 1.6 percent, while the tech-heavy Nasdaq Composite lost 3 percent and the S&P 500 dropped by 1.7 percent. Stock futures fell further early Tuesday, Fox Business reports, suggesting more tech-fueled selling. Harold Maass

White House Press Secretary Sarah Huckabee Sanders faced some tough questions on Monday about her claim that President Trump has been totally exonerated on obstruction of justice.

Sanders was interviewed on Today the morning after Attorney General William Barr released his summary of Special Counsel Robert Mueller's report into Russian interference in the 2016 election. The White House has called the findings a complete exoneration, but while the summary does say Mueller found no evidence of collusion with Russia, Mueller specifically says Trump is not exonerated on obstruction and that he was leaving this determination to the attorney general. It was Barr and Deputy Attorney General Rod Rosenstein who subsequently determined there was insufficient evidence to show Trump obstructed justice.

Today's Savannah Guthrie made this point during her interview with Sanders on Monday, asking her, "Would you acknowledge it is incorrect for the president to call this a total exoneration?" Sanders' response? "Not at all. It is. It is a complete and total exoneration."

Sanders' basic argument was that Trump is still exonerated based on Barr and Rosenstein's conclusions, which resulted from evidence obtained by Mueller, even if Mueller himself did not make a determination either way. Guthrie raised some criticism that has been leveled at Barr, namely that he made his determination on obstruction in 48 hours after having previously said there was no obstruction of justice case against Trump, suggesting perhaps he made a "snap judgment."

"It's not a snap judgment," Sanders responded. She went on to say that "in the legal commnuntiy, when you can't convict somebody on something, you're exonerating them." Guthrie objected to this idea, responding, "You're not." Watch the exchange below. Brendan Morrow

Special Counsel Robert Mueller's final report, as summarized by Attorney General Robert Barr, lays down "one proposition unambiguously: The special counsel's office did not believe that it could reasonably prove in court that any Trump campaign member or affiliate committed a crime in assisting the Russian government with its efforts," Lawfare writes. "It means there is no smoking gun. ... That's good news, in general, and it's good news for President Trump."

But Mueller explicitly did not exonerate Trump on obstruction of justice. Barr wrote that he and Deputy Attorney General Rod Rosenstein had determined Mueller's evidence "is not sufficient to establish the president committed an obstruction-of-justice offense," but "a source with direct knowledge of the investigation told The Daily Beast that it was their interpretation that 'Mueller was making a case to Congress, who (unlike DOJ, in Mueller's view) is empowered to weigh the lawfulness of a president's conduct.'"

Barr's letter "leaves the distinct sense that Mueller's detailed accounting of the president's potential acts of obstruction is significant," and "that may well be the point," Lawfare agrees. An obvious reason Mueller, "being barred from indicting the president," would lay out an extensive case for and against criminal obstruction but not give his prosecutorial opinion is that he's "teed up the question of presidential obstruction for evaluation by a different actor — to wit, by Congress."

Barr's letter actually "seems to suggest that Trump may have done impeachment-worthy things, but not prosecution-related things," Marcy Wheeler argues at Emptywheel. "Mueller found that no Trump flunkie took part in either of the two main Russian interference attempts," and "Barr and Rod Rosenstein, together, decided because Trump did not take part in those two interference attempts, he could be not charged with obstruction," regardless of whether he "was trying to cover up some other crime, like a quid pro quo, which would still merit prosecution." House Democrats should focus on that, Wheeler suggests. Peter Weber

The White House is understandably relieved about Special Counsel Robert Mueller's Russia investigation concluding with no more indictments or evidence of criminal conspiracy by President Trump or his campaign. Trump's 2020 re-election campaign is aggressively fundraising off of the report, or at least the four-page summary released by Attorney General William Barr on Sunday. But as veteran newsman Dan Rather pointed out, the positive headlines may not be the end of the story.

"Even if the actual Mueller report is anything like the attorney general's summation of its contents, Russiagate will go down as one of the biggest scandals in American political history," argues Franklin Foer at The Atlantic:

The Mueller investigation has been an unmitigated success in exposing political corruption. In the case of Paul Manafort, the corruption was criminal. In the case of Trump, the corruption doesn't seem to have transgressed any laws. As Michael Kinsley famously quipped, "The scandal isn't what's illegal; the scandal is what's legal." Lying to the electorate, adjusting foreign policy for the sake of personal lucre, and undermining an investigation seem to me pretty sound impeachable offenses — they might also happen to be technically legal. [Franklin Foer, The Atlantic]

Among other things, "Mueller has also provided a plausible answer" to why Trump "couldn't stop praising Vladimir Putin," and still sides with the Kremlin over the U.S. government, Foer writes. "Trump's motive for praising Putin appears to have been, in large part, commercial," and his mendacious attempts to use the campaign and U.S. foreign policy to enrich himself "is the very definition of corruption, and it provides the plot line that runs through the entirety of Trump’s political life." Read Foer's entire argument at The Atlantic. Peter Weber

According to Attorney General's summary of Special Counsel Robert Mueller's final report, as well as previous Mueller court documents, Russia ran two sophisticated campaigns to interfere in the 2016 U.S. presidential campaign on President Trump's behalf. But you wouldn't know that from the "gloating" that's "already begun in Moscow," says Nathan Hodge at CNN.

"In short, Russia did not elect Trump," Evgeny Popov, co-host of a pro-Kremlin political talk show, tweeted. "Mueller did not find evidence of collusion between Trump's team with Russia. The U.S. attorney general submitted a 4-page report on the special prosecutor's investigation report to Congress. D is for Disappointment." Alexey Pushkov, a high-profile Russian senator, called Democrats "conspiracy theory maniacs."

On CNN Sunday night, former counter-intelligence officer Steve Hall posited one reason for Russia to cheer the Mueller report. "The Russians are probably a bit surprised at how broad they can go, and next time they go against us in a hybrid-warfare type of fashion, at the very least in 2020, they’ll know that they can probably push a little bit further," he told Don Lemon. "What they’ve learned is due to our system of justice, due to our open society and how things work here, they actually have a lot more room to work with, and still people aren’t going to be thrown into jail — or, at least, the most important people aren't going to be accused of the worst things."

In fact, the danger Russia poses to America's democracy seems to be the one thing both parties — at least in Congress — can agree on from Mueller's report. Senate Majority Leader Mitch McConnell (R-Ky.) welcomed Mueller's "contributions to our efforts to understand better" Russia's "dangerous and disturbing" and "ongoing efforts to interfere with our democracy." The No. 2 Senate Republican, Sen. John Cornyn (R-Texas), said the Russians "have and always will try to create problems for democracies. We need to expose it and defeat it." Peter Weber

The obvious highlight for President Trump from Attorney General William Barr's four-page summary of Special Counsel Robert Mueller's investigation is this sentence from Mueller's report: "[T]he investigation did not establish that members of the Trump campaign conspired or coordinated with the Russian government in its election interference activities," expressly or tacitly. Translated by Trump and his circle, that reads: NO COLLUSION.

But "Trump's triumphant supporters notwithstanding, we don't yet know what that means," former federal prosecutor Ken White explains at The Atlantic:

When prosecutors say that an investigation "did not establish" something, that doesn't mean that they concluded it didn't happen, or even that they don't believe it happened. It means that the investigation didn't produce enough information to prove that it happened. Without seeing Mueller's full report, we don't know whether this is a firm conclusion about lack of coordination or a frank admission of insufficient evidence. [Ken White, The Atlantic]

Barr also cites only Mueller's lack of evidence that the Trump campaign conspired or coordinated with "Russia's government," William Saletan notes at Slate. This would appear to leave out several key interactions with Russians, like Trump campaign chairman Paul Manafort secretly giving reams of polling data to Konstantin Kilimnik, or Donald Trump Jr. and Jared Kushner meeting in Trump Tower with Kremlin-linked lawyer Natalia Veselnitskaya, who was purportedly offering dirt on Hillary Clinton.

Similarly, Barr limits the collusion exculpation to two specific Russian operations: the strategic, targeted manipulation social media and the hacking and dissemination of emails from Clinton's campaign and the Democratic National Committee. Other apparent quid pro quo discussions "between Trump associates and Russians, such as Trump's Moscow tower project and Michael Flynn's secret talks about easing sanctions, have been set aside," Saletan argues. Barr's letter "doesn't show that Trump is innocent of collusion or obstruction. It shows that collusion and obstruction were defined to exclude what he did." Peter Weber

House Speaker Nancy Pelosi (D-Calif.) and Senate Minority Leader Chuck Schumer (D-N.Y.) released a joint statement on Sunday, saying that the letter Attorney General William Barr sent to Congress giving his summary of Special Counsel Robert Mueller's report "raises as many questions as it answers."

According to Barr's letter, Mueller's report does not exonerate President Trump "on a charge as serious as obstruction of justice," and this "demonstrates how urgent it is that the full report and underlying documentation be made public without any further delay," the Democratic leaders said. "Given Mr. Barr's public record of bias against the special counsel's inquiry, he is not a neutral observer and is not in a position to make objective determinations about the report."

Pelosi and Schumer are referring to a memo Barr wrote last year and sent to senior Justice Department officials in June. Barr, at the time a private citizen, wrote that he thought Mueller's investigation into obstruction of justice was "fatally misconceived." Trump nominated Barr after firing former Attorney General Jeff Sessions in November.

After the letter was released, Trump erroneously stated that the Mueller report "completely exonerated" him, and Pelosi and Schumer said Trump's statement "is not to be taken with any degree of credibility. Congress requires the full report and the underlying documents so that the committees can proceed with their independent work, including oversight and legislating to address any issues the Mueller report may raise. The American people have a right to know." Catherine Garcia