President Donald Trump and his allies are leaning heavily into a new 2020 strategy tying Democrats and their presumptive presidential nominee Joe Biden not just to China but to its role in spreading the coronavirus.

Democrats are increasingly worried that the strategy will work.

The Trump re-election campaign released a new ad this week going after Biden over his opposition to restrictions on travel from China designed to control the spread of the coronavirus outbreak. That was followed with a fundraising solicitation on Saturday that hammered home the point: “I am TOUGH ON CHINA and Sleepy Joe Biden is WEAK ON CHINA,” it declared.

Inside the campaign, the strategy is simple: make China the villain of a global pandemic that has complicated well-laid electoral plans and sparked growing criticism of the president.

“[China’s] among many weaknesses, but when people learn about Biden’s attack on the president’s China travel ban, his other weak positions on China, and his conflict with Hunter Biden’s business deal with China, voters are horrified,” John McLaughlin, a Trump pollster, told The Daily Beast on Friday. Other Trump 2020 officials said that the campaign had always intended to hammer Biden on China until the election in November, and the coronavirus “angle” was merely another way to go after the Bidens and China simultaneously.

In one sense it’s simply an extension of Team Trump’s months-long strategy to tie Biden to a country increasingly viewed with suspicion by American voters. The campaign and the Republican National Committee have been hammering Biden for months over his youngest son Hunter’s past business dealings in China.

But the outbreak of the novel coronavirus, which originated in the Chinese city of Wuhan, has made the country a far more potent political villain. And the massive disruptions in daily life caused by the virus virtually guarantee that China will remain in the headlines—and on the minds of American voters—for months as election day approaches. Polls already indicate that Americans of both parties overwhelmingly blame China for the virus’ initial spread.

For a Trump campaign that’s a potential political goldmine. “China was an effective wedge issue for Trump in 2016,” said one Republican strategist close to the campaign. “Now that it’s at the top of everyone’s mind, and Biden has a long record of being weak on China, just imagine how much more effective it will be in 2020.”

The new tactic from Trump has not gone unnoticed by Democrats who fear that it may be the type of opening that a cynical president could effectively use—even one who has made a point of going soft on China’s leader, Xi Jinping, whom Trump routinely praises as an “incredible guy” who’s doing a great job handling the virus.

Navigator Research, a progressive polling outlet that has taken the lead for the party in public opinion surveying around the virus, included an alarm bell nugget in its Friday dispatch. “Warning” the item read, “Trump’s China rhetoric may be resonating and gaining traction.” As evidence, the firm noted that 43 percent of respondents in its survey said “China bears more responsibility than the federal government for the way coronavirus has spread in the U.S.”

“A lot of times people on the left tend to have a knee-jerk reaction to Trump's racism and xenophobia that disallows them from taking it as seriously as a messaging tactic as it is,” said Ian Sams, a consultant for Navigator. “The public is pretty anti-China right now. And I think there is validity to the idea that they’ve been less than transparent and hid information on this virus. And Trump is seizing on that… We can’t just let Trump’s lies be the only thing out there.”

To that point, Democrats have largely stopped pushing back against Trump’s anti-China push on grounds that it’s xenophobic and adopted the posture that it’s all a big lie, pointing to, among other things, the fact that his administration sent China medical supplies as it was battling coronavirus, only to then have a shortage of them when it hit the U.S.

Democratic National Committee talking points, obtained by The Daily Beast, say that Trump’s claim to have “acted early with his China travel restrictions,” was in reality “too little too late.” The Democratic Party’s top think tank, Center for American Progress, put together a memo that encouraged officials not to “concede a thing on Trump’s travel ban.”

“The reality is, Trump was slow in instituting the ban,” it reads. “And the ban was so leaky that 40,000 more people entered from China after the ban was in place.”

But Sams conceded that it likely would not be good enough to merely call Trump a liar on China. The case needed to be made, he said, that the president had coddled Beijing at a time when the country should have been warning the U.S. about the seriousness of COVID-19.

Top Democratic officials said that they were gearing up to more proactively make that point in the days ahead. And Biden’s campaign, for its part, seems to be there already.

“Despite repeated warnings from the U.S. intelligence community—and public warnings from Joe Biden—that he shouldn't take China's word about containment of the outbreak, Donald Trump praised China's response for weeks while downplaying the threat to us,” said Andrew Bates, a Biden campaign spokesman. “Now we have the most coronavirus cases in the world and we’re losing millions of jobs. Any time Donald Trump says the word ‘China,’ he accomplishes one thing: reminding the American people of his historic failure to prepare our nation for the worst public health crisis in generations.”

Indeed, this comes at a time when Trump’s poll numbers on his handling of the coronavirus crisis have seen significant dips in recent days. In late March, major public polls showed a spike in how the American people judged the president’s response to the pandemic and collapsing economy. White House officials were delighted that they were able to print out and slip into Trump’s reading materials some favorable coverage, including this Fox News article titled, “60 percent of Americans approve of Trump’s handling of coronavirus: Gallup poll,” said a senior administration official.

White House staff knew how much this would please the president and were confident he would incorporate the news into his daily messaging. However, as Trump’s poll numbers on the virus slumped, these aides quickly stopped including the newer data in the president’s daily batches of articles and reading material, for fear it would “upset him,” the official added.

Some Trump allies, though, are convinced that they can both ding Democrats’ presidential nominee and boost their own public profiles—and standing with the president himself—by invoking China’s role in the coronavirus’ spread. Sen. Tom Cotton (R-AR) even went so far as to buy television ads in Ohio ahead of that state’s Democratic presidential primary attacking Biden on the China issue.

Cotton and other Senate Republican China hawks, such as Missouri’s Josh Hawley and Texas’ Ted Cruz, have found China-bashing to be an effective strategy in its own right. All three have taken out Facebook ads criticizing the country for its role in the spread of the coronavirus.

Outside advocacy groups have gotten in on the action as well. Stand Up to China, a new dark money outfit, has spent about $36,000 on Facebook ads hammering Beijing on issues from the coronavirus to its mass internment of Uyghur Muslims. It’s not clear who, exactly, is behind the group, which has targeted the vast majority of its anti-China ads at Facebook users in Florida.

Perhaps the most dramatic China-themed advertising, though, has come from Kathaleen Wall, a Republican House candidate in Texas. In a video ad that began airing last week, she dubs China a “criminal enterprise masquerading as a sovereign nation,” which “has poisoned our people.”

“President Trump has the courage to call it what it is,” the 30-second spot says, with a clip of Trump referring to “the Chinese virus.” The ad promises, “Kathaleen Wall has his back.”