Each December, the nonpartisan fact-checking website PolitiFact chooses the year's biggest falsehood. But in 2015, thanks to Republican presidential frontrunner Donald Trump, they couldn't select just one claim worthy of being Lie of the Year. So instead, that honor went to all of Trump's campaign misstatements.

Of the 77 Trump claims PolitiFact has tackled so far, 76 percent of them have rated Mostly False, False, or Pants on Fire.

"Trump hasn't apologized or backtracked on his statements," PolitiFact notes. "Instead, when challenged, he offers flimsy explanations and suggests he shouldn’t be held accountable — or simply insists he's right."

Read PolitiFact's full breakdown of Trump's consistent aversion to facts here. Julie Kliegman

It's official: Salesforce has unveiled plans to acquire Slack in a $27.7 billion deal.

The company on Tuesday announced the Slack acquisition, the biggest deal since Salesforce's founding, The New York Times reported. The news came after The Wall Street Journal reported that the deal for the software company was in advanced discussions.

Salesforce CEO Marc Benioff described the purchase of Slack as "a match made in heaven," while Slack CEO Stewart Butterfield called this the "most strategic combination in the history of software."

Salesforce's acquisition of Slack will still need to receive approval from regulators and Slack shareholders, the Journal notes. But should it go through, the Journal writes that it would "turn the combined company into one of the biggest players in the competitive business-software market." Slack has said there has been a "significant increase in demand and usage" due to increased working from home during the COVID-19 pandemic, and in the three months that ended in October, its revenue rose 39 percent, the Times reports.

But analysts note this deal comes as Slack "faces heavy competition from Microsoft's Teams product," The Washington Post reports.

"When you're a scrappy start-up going against an 800-pound gorilla that's one of the most well-capitalized companies in existence, it's tough to compete," analyst Logan Purk told the Times. "This is more or less saying, 'We can't compete with Microsoft Teams anymore. We need more firepower.'" Brendan Morrow

The Centers for Disease Control and Prevention will advise health care workers and long-term care facility residents receive COVID-19 vaccinations first, if and when Food and Drug Administration approval is granted.

The decision was reached by the Advisory Committee on Immunization Practices, which is advising the CDC on vaccine distribution practices. As vaccine approval for emergency use becomes increasingly likely in the coming weeks, the panel voted 13-1 in favor of a motion elevating two groups to the front of the line. Health care workers are frequently exposed to the virus and are essential to keeping hospitals running throughout the pandemic, while nursing homes have faced some of the deadliest COVID-19 outbreaks across the country.

The lone vote against the priority recommendation came from Dr. Helen Kiepp Talbot, who clarified that she has no reservations about health care workers receiving the vaccines, but is concerned there is not enough data on the safety and efficacy of the vaccine candidates nearing approval in older adults, who are more likely to live in long-term care facilities. Tim O'Donnell

President Trump's campaign lawyers have an unexpected new enemy.

Attorney General William Barr took a surprising step away from Trump on Tuesday, telling The Associated Press the Justice Department has so far not found any major instances of voter fraud. Trump's legal team, including Rudy Giuliani and Jenna Ellis, quickly fired back, claiming Barr just doesn't have enough evidence to clear every fraud allegation.

"With all due respect to the attorney general, there hasn't been any semblance of a Department of Justice investigation" into the allegations of voter fraud Trump's team has gathered. If Barr just looked at Giuliani's "many witnesses" and "audited" some voting machines, the legal team insists he'd find some fraud; Election officials across the U.S. say there's been no evidence of widespread fraud that would change the election outcome.

In an interview with AP, Barr said the department had "not seen fraud on a scale that could have affected a different outcome" in the presidential election last month. President-elect Joe Biden beat Trump, but the president and most of his team has yet to acknowledge that, levying legal challenges and furthering conspiracy theories in a longshot attempt to overturn the election results. Judges have almost universally knocked down the Trump campaign's challenges and voter fraud allegations. Kathryn Krawczyk

A few hours after a bipartisan group of senators unveiled a $908 billion coronavirus relief bill proposal Tuesday, Senate Majority Leader Mitch McConnell (R-Ky.) circulated his own plan among Republican lawmakers. Several news organizations obtained a copy of the outline.

McConnell's plan, Bloomberg notes, appears to be a tweaked version of his previous $500 billion proposal (although the full price tag is not yet known), with funds earmarked for a second round of the Payroll Protection Program and coronavirus vaccine distribution and development. It doesn't seem likely to serve as an overture to Democrats and instead caters to several Republican senators by including measures like COVID-19 liability shields for businesses, which the other side of the aisle opposes.

Unlike the bipartisan framework from earlier in the day, McConnell's bill does not include any money for state, local, and tribal governments, another nod toward Republicans who remain staunchly opposed to the notion. It does extend the deadline for enhanced unemployment benefits, but only by a month, whereas the other bill proposal would push end date to April.

McConnell said he was bearish on his colleagues' framework because the clock is ticking, and he seems to believe the White House will sign off on his version. Tim O'Donnell

Attorney General William Barr announced Tuesday he has appointed U.S. Attorney John Durham, who was previously tasked with investigating the 2016 Russia probe's origins, as special counsel.

Barr told The Associated Press that he appointed Durham as special counsel in October, explaining that ahead of the 2020 presidential election, "I decided the best thing to do would be to appoint them under the same regulation that covered Bob Mueller, to provide Durham and his team some assurance that they'd be able to complete their work regardless of the outcome of the election."

An order obtained by AP states that Durham is authorized to "investigate whether any federal official, employee or any person or entity violated the law in connection with the intelligence, counter-intelligence or law enforcement activities" while probing allegations of cooperation between Trump's campaign and Russia. Documents show that Barr "made the appointment on October 19 and kept it secret so as not to interfere in the election," CNN writes.

Durham will now have additional protection, as a special counsel can only be fired by the attorney general for certain reasons, AP notes. Barr's announcement of his October appointment came on the same afternoon that he told AP the Justice Department has found no evidence of widespread voter fraud that would change the results of the 2020 election. Brendan Morrow

One of Georgia's top election officials has a harsh message for President Trump and his continued conspiracy theorizing.

Trump has yet to acknowledged President-elect Joe Biden won Georgia and the whole presidential election a month ago, preferring to doubt the accuracy of the vote and rail against Georgia officials of his own party. And in a Tuesday press conference, Gabriel Sterling, a Republican and Georgia's voting system implementation manager, made it clear Trump has gone too far.

In a direct message to Trump, Sterling said that "it looks like you likely lost the state of Georgia," though the president "has the rights to go through the courts" and wait for a formal recount before conceding. "But what you don't have the ability to do, and you need to step up and say this, is stop inspiring people to commit potential acts of violence," Sterling forcefully said. "Somebody's going to get hurt, someone's going to get shot, someone's going to get killed."

Sterling went on to bring up Joe diGenova, a Trump campaign lawyer who called on fired cybersecurity official Chris Krebs to be "taken out at dawn and shot." Election workers in Georgia have also had death threats, with one in Gwinnett County told he should be "hung for treason," Sterling added. He once again turned to call out Trump and Georgia's Republican Sens. Kelly Loeffler and David Perdue for failing to "condemn this language" and "these actions." "This has to stop," Sterling finished. Kathryn Krawczyk