The New Hampshire Senate race is ground zero for the new national-security campaign that Republicans are waging across the country in the closing weeks of the midterm elections. It goes like this: World events are out of control. President Obama is a weak leader. Elect Republicans if you want strong leadership.

Republican Scott Brown, the former Massachusetts senator now running in the Granite State, is the best conveyor of the message. In a television ad that makes him look fresh off the front lines of military action, he wears camouflage fatigues, then is seen standing tall in his National Guard dress uniform as a narrator declares: “Scott Brown spent 35 years in the Army National Guard. He knows what it takes to keep America safe.”

Democrat Jeanne Shaheen was once so far ahead that Brown’s quixotic move across state lines in his quest for a Senate seat wasn’t taken seriously. Now he has closed the gap to single digits, and he’s making a big push in these final weeks. Delivering the weekly Republican address over the weekend, he described a world “on fire… So many challenges, so many threats and problems, and all at the same time. This is what the world looks like without American leadership.”

This is the GOP message, and the second case of Ebola reported in Dallas “is this chaotic world brought back to America,” says William Galston, senior fellow at the Brookings Institution. “It’s imported chaos.” And the spread of the virus dovetails with the narrative that Republicans are promoting, that if Obama were somehow a stronger leader he’d have control over all this. “However much of a fantasy that is,” says Galston, “things can be powerful even when they’re not plausible.”

Brown doesn’t explicitly mention Ebola, but other Republicans on the campaign trail link it to calls to “seal the border,” as Republican Thom Tillis did in a debate with North Carolina incumbent Democrat Kay Hagan. “Ladies and gentlemen, we’ve got an Ebola outbreak, we have bad actors that can come across the border. We need to seal the border and secure it,” Tillis declared. Analysts pointed out that someone suffering from Ebola could hardly make the arduous journey from West Africa and across Mexico, but pesky facts take a back seat to emotion in the closing days of an election.

An email arrived in my inbox early Monday with the subject line “If you die, blame them,” announcing an ad campaign called “Republican Cuts Kill” that will begin airing next week in Kentucky, “with North Carolina, Kansas, and South Dakota to follow provided we complete the financing we need.” The 60-second ad is brutal, featuring images of health-care workers in hazmat suits, suffering West Africans, and corpses in the street, all serving as the backdrop to a litany of Republicans calling for cuts in the budgets of the Centers for Disease Control and Prevention, the National Institutes of Health, and infectious disease control programs. The numbers flash on the screen: $585 million in cuts since 2010 for the CDC alone. NIH head of infectious diseases, Anthony Fauci is seen in testimony on Capitol Hill calling the cuts in government programs “a left hook” followed by “a right cross.” CDC Director Thomas Frieden is also seen in the ad deploring the slowdown in funds.

The progressive group that launched the ad, Agenda Project Action Fund, backs it up with a report detailing the voting record and public comments of more than two dozen Republicans. The group alleges that the GOP’s “fanatical hatred for our government” is at least partially responsible for the inability to deal with the Ebola crisis before it reached the United States. “Republican Cuts Kill” is printed across the screen, with the only sound a person struggling to breathe through a respirator.

Such charges of budget malfeasance, however factual, could backfire if Democrats are seen as the party that is politicizing the Ebola crisis. The Agenda Project Action Fund is known for playing close to the line, with a 2012 ad accusing Republican Paul Ryan of throwing granny off the cliff and a memorable “Romney Girl” spoof.

But leaving the field open to the GOP to play on people’s fears of a world spinning out of control is not a good alternative for Democrats. Within hours of the announcement of the Agenda Project’s visceral ad, the Democratic Congressional Campaign Committee announced that it was running paid online ads to highlight Republican votes to cut the CDC budget while continuing to support tax breaks for special interests.

The DCCC quotes remarks Dr. Fauci, head of the NIH, made Sunday: “Frankly, if we had not gone through our 10-year slide in research support, we probably would have had a vaccine in time for this that would’ve gone through clinical trials and would have been ready.” The Web ad sticks to the facts. On one side of the screen, it says, “Republicans Voted to Cut CDC’s Budget to Fight Ebola”; on the other side, it says, “Republicans Protect Tax Breaks for Special Interests.” The votes and the dates are cited, and that’s it.

The ad is almost too tame, and it didn’t provoke much response from the National Republican Congressional Committee. Andrea Bozek, the NRCC’s communications director, told The Daily Beast: “They’re Web ads. If they were real ads, they’d put them on TV. They’re grasping at straws, using an international health crisis as a political tool.”

After all the assurances from government officials, including Obama, that Ebola couldn’t spread here, it just did in Dallas over the weekend, even with all the protocols in place. “It won’t take more than another few instances of transmission in the U.S. to generate something approaching panic,” says Galston. “We’re on very thin ice now, and I hope the administration knows it.”

Republicans know it, and they see an opening to sway tight races with an appeal to voter fears about a world Obama can’t control, and a virus that is mysterious and terrifying.

Correction: An earlier version of this article referred to Fauci as the head of NIH.