New York (CNN Business) A version of this article first appeared in the "Reliable Sources" newsletter. You can sign up for free right here.

Last Monday, Tucker Carlson delivered a warning on his Fox News show. He said the coronavirus posed a great threat. He said it was much more severe than the flu. And he said that people have "spent weeks minimizing what is clearly a very serious problem." While he delivered that monologue, his colleague Trish Regan was on Fox Business dismissing coronavirus as nothing more than an attempt to impeach Trump.

"Since then, just 168 hours have passed, not even enough time to watch every episode of 'The Simpsons' and in that time, everything has changed," Carlson said Monday. Indeed, everything has changed, including Fox News' overall coverage of the lethal virus.

Regan is no longer on the air. And Fox's biggest stars are no longer denying the crisis. "With Trump's declaration on Friday that the virus constitutes a national emergency, the tone on Fox News has quickly shifted," wrote WaPo's Paul Farhi and Sarah Ellison in a Monday story. Farhi and Ellison summarized, "In all, it has been a complicated dance for a network whose hosts are among Trump's most ardent boosters and defenders — an increasingly challenging position to take as the crisis grew in magnitude."

Watters' World rocked

On "The Five" Monday, host Jesse Watters admitted that he "didn't take the social distancing that serious" over the weekend. Watters said he "went out to dinner" in NYC. "And I woke up this morning I realized that was not the right move. I am no longer going out to dinner," Watters said. The contrast between last week and this week was visually on display as well. "The Five," like other shows on Fox and other networks, practiced social distancing on Monday's episode.

Comes with change in Trump's tone

"Welcome to the pandemic, Mr. President," Chris Cuomo said to kick off his show Monday night. NYT's Thursday A1 said, "With economy in peril, Trump urges caution." Like Fox has done in the last few days, it seemed that at Monday's press conference, Trump recognized the reality of the public health emergency. He acknowledged the dire situation and explained what needs to be done to tackle it. He even said the media has been "very fair."

"It's like we got a different POTUS," Jim Geraghty noted . Phillip Bump seemed to agree, writing, "First time I've seen Trump speak on this without significantly downplaying things." And Josh Barro tweeted, "Today is the first day in a while that I feel more optimistic about this thing than I did the previous day. Feels like government responses are getting closer to what they need to be."

Why Fox's coverage is so important

Given that Republicans largely turn to Fox for their news, it's likely the network's previous dismissive coverage has affected how Republicans view the crisis. A Gallup poll published Monday found that "political party identification reflects the starkest differences in levels of worry about coronavirus exposure."

According to the poll, "Democrats (73%) are the most worried of any group, and their level of worry has increased the most out of any group. Meanwhile, less than half of Republicans (42%) report having this level of concern -- the lowest of any group Gallup measured." Hopefully things will change with the network's shift in tone...

That's not to say partisanship has disappeared from Fox

While Fox News is certainly taking the coronavirus more seriously, that's not to say that partisanship has vanished from the network. Yes, Sean Hannity encouraged viewers on Monday to "flatten that curve" to save lives. But he also made time for praising of Trump and attacked those he claimed are "more interested in bludgeoning the President than actually solving a problem."

Nunes attacks "media freaks"

Hannity, for instance, allowed Devin Nunes to misrepresent his Sunday coronavirus comments unchallenged on his program Monday night. Nunes, you'll remember, spread dangerous misinformation on Maria Bartiromo's Fox show Sunday, telling Americans it was a "great time to go out and go to a local restaurant." Nunes told Baritromo "likely you can get in easy" and told people, "Go to your local pub."

On Monday's episode of Hannity, Nunes attacked "media freaks" and said they "don't have a clue what's going on in the real world." Nunes claimed he meant Americans should order take out or use drive-thru. And then he attacked "media freaks" saying *THEY* are the ones "endangering lives" by "continuing this panic when we have no food shortage in this country." Of course, Hannity didn't challenge Nunes on any of these assertions...

FOR THE RECORD

-- Chris Cuomo on CNN Monday night: "We may be forcing ourselves deeper into isolation -- and we should -- but this effort, this war, may bring us closer together than we imagined." ( Twitter

-- Rachel Maddow: Among officials in New York state, "the fear is palpable, because they see this coming..." the surge of sick people needing hospitalization is days, not weeks, away...

-- With "Jimmy Kimmel Live" in repeats, "Nightline" has moved back to 11:35 p.m. Brian Steinberg has details... ( Variety

-- "SNL" has suspended production... ( CNN

-- Rachel Abrams reports from inside the Seattle Times, one of the local newspapers at the center of the coronavirus pandemic... ( NYT