The remaining Democratic presidential candidates have united in the last week on a core message: The coronavirus outbreak proves how important it is to defeat President Donald Trump.

The global health crisis - which has rattled global markets and has now been reported in multiple western US states without known connections to the virus’ spread in Asia - has been woven into virtually every Democratic candidates’ messaging in the last week, with just days to go before the biggest primary day of the year.

Michael Bloomberg is airing an ad titled “Pandemic” across TV nationwide. Elizabeth Warren put out an early plan for preventing the spread of infectious diseases. Amy Klobuchar has talked about containing the virus as a way of transcending partisan politics. And Joe Biden, Bernie Sanders, Pete Buttigieg, and Tom Steyer are all talking about the virus as they campaign ahead of the South Carolina primary on Friday and in 16 Super Tuesday contests next week.

The common factor: Each candidate has turned the outbreak into a new, potent critique of Trump, hitching their individual campaign messaging to a story that has otherwise begun to pull Americans’ attention away from the presidential election.

As the president has contradicted warnings from health officials and focused on controlling messaging around the outbreak by placing Vice President Mike Pence in charge of the response, Sanders, the frontrunner in the Democratic primary, has sent a series of statements from his campaign this week on Trump’s “inadequate, misleading, and dangerous” handling of the crisis.

“It turns out that Donald Trump is in Charleston today,” he said at a Friday morning campaign event in St. George, South Carolina, of the rally Trump had planned later that night.

In stops across the state on Friday, the day before the South Carolina primary, Sanders repeatedly accused Trump of meddling in the Democratic nominating process by holding a rally here when he should be focusing on the ongoing health crisis.

“Now, I want you to think - think about what it says about this guy,” Sanders said in St. George. “Everybody knows there is a coronavirus spreading all over the world. Very frightening, stock market is tanking. You would think that you'd have a president of the United States leading - working with scientists all over the world, bringing people together to figure out how we're gonna deal with this crisis. He is here in South Carolina. He doesn't even have any opposition in the Republican primary - why is he here? He's here to try to disrupt the Democratic primary. How pathetic and how petty can you be?”

Elsewhere in the state, Buttigieg centered his more typical argument for generational change in politics on the virus. “This is not a kind of national security issue that we’re used to dealing with from the past,” he said in Charleston on Friday. “This virus does not care what country it is in. It’s not going to be stopped by a big wall. These kinds of issues, whether it’s global health security, cyber security, election security, are going to require a focus on the future, just as right here at home.”

In Summerville, SC, Steyer told an audience that coronavirus would have a profound economic impact on the United States and other countries and slammed the Trump administration’s response.

“This is Trump’s incompetence in a neon sign going like, ‘I stink at my job. Yeah, I am a dummy! Ok?’ by Donald Trump,” Steyer told the crowd. “This was announced on December 31st, he is so late on this that it’s crazy. He’s two months late to do anything.”

Steyer told the crowd that Trump’s response had been inadequate and that the spread of coronavirus was Trump’s “Katrina.”

“It’s his moment where he’s like, ‘whoa! I have a job to do? Who knew!’”

Bloomberg has talked about the US response to the virus as a management failure from the Trump administration, contrasting it with his own experience in New York City and at his company. He mentioned the coronavirus epidemic at the top of his remarks during campaign events on Thursday, Friday, and Saturday in several Super Tuesday states. Bloomberg slammed Trump’s “incompetence” in dealing with the virus and accused the president of “burying his head in the sand.”

“This week, the stock market has plunged partly out of fear,” Bloomberg said on Friday morning at a rally in Memphis. “But also because investors have no confidence that this president is capable of managing the crisis.”

“The market is pricing in the president’s management incompetence and we are going to pay a heavy cost for that, in addition to the more serious health crisis we face,” Bloomberg said. “We have to first worry about our health, but the economy is also the way we make a living.”

Biden has also been sticking closely to his own experience when he’s talked about coronavirus this week, frequently beginning by talking about the Obama administration’s response to the Ebola crisis in 2014. On Friday, Biden directly criticized how the Trump administration has reportedly asked Anthony Fauci, head of of the National Institute of Allergy and Infectious Disease, not to speak about the virus without White House approval.

“We didn’t do it by silencing scientists,” the former vice president said Friday night in Spartanburg, South Carolina. “You notice what has been recently said. The president of the United States and Vice President Pence told Mr. Fauci, one of the leading scientists in the world on pandemics, he was not able to speak out. The scientists have been silenced. This president makes everything personal. He thinks that this coronavirus is a conspiracy to defeat him. No, I mean, look at what they’re saying."

Biden got more pointed from there.

"This may be the one place and a concrete example of where the reputation for a president to tell the truth is of great consequence,” he said. “No, I really mean it, think about it. When he tells you, don’t worry, or worry, how many of you can go to the bank on that?"

Candidates are also beginning to reckon with the fact that an outbreak in the US, along the lines of what the Centers for Disease Control suggested is possible, could radically disrupt normal campaigning in the coming weeks.

In an interview with BuzzFeed News in McLean, Virginia, on Saturday, Bloomberg wouldn’t rule out cancelling upcoming campaign events if the virus continues to spread.

"I think you can't say never,” he said. “I think it's unlikely that it will get that bad. But you have to prepare for everything, that's the problem with Trump, he doesn't prepare for anything.”

Bloomberg criticized Trump for calling the virus a “hoax” — “how dumb can you be?” he said — and said, “you have to assume the worst when you're preparing, [it] doesn't mean you have to change your life until you find out how bad it is. But the president is supposed to be way ahead and getting ready for the worst case scenario just because that's the way you have to do it, you're going to save lives."