For months now, procuring a vaccine for Covid-19 in America has been almost as easy as getting a haircut. Jabs have been widely available since the spring and no one who wants to get vaccinated has any good reason to not be well on their way to immunity. The supply side of the US vaccination story has, in other words, been a thumping success.

Things are less heartening on the demand side, which is why President Joe Biden missed his target of 70 percent of adults having received their first dose by July 4. The figure is stuck around the 68 percent mark. About half a million Americans are getting a shot each day, down from a daily peak of nearly 3.5 million in April.

To some, these numbers reflect a straightforward and very political tale of Republican idiocy. “Populist conservatives are to blame,” concluded the Economist this week. CNN’s Chris Cillizza pointed the finger at the “Trump/freedom train”.

To be sure, the partisan split on vaccination is stark. According to a recent ABC/Washington Post poll, 86 per cent of Democrats have received at least one dose of the vaccine compared to 45 per cent of Republicans. More than a third of Republican respondents say they are certain they will not take the shot. Underscoring the point is the gap in vaccination rates between states that voted Trump and those that voted Biden, with the reddest states being the places with the lowest vaccination rates. And with cases ticking up and the delta variant spreading across America, swathes of the country are likely to pay a high price for that deficit.

But however undeniable these numbers appear, is it really a simple as party politics? As Chris Stirewalt pointed out in The Dispatch this week, exactly what is causation and what is correlation is far from clear.

Vaccine hesitancy is most common among low-income Americans without a college degree. They also happen to be the part of the electorate most likely to support Trump. But does the former lead to the latter? Yes, MAGA-friendly Republicans have embraced vaccine scepticism. Ron Johnson, a senator from Wisconsin, is locked in a disingenuous “just asking questions” anti-vaxx campaign. Prime time Fox News presenter, Tucker Carlson, who won’t say if he has been vaccinated himself, hosts debunked cranks who talk up the supposed dangers of getting jabbed.

But the profile of America’s vaccine scepticism is more muddled than all of this might make you think. A Morning Consult survey from April broke down unwillingness to get vaccinated by demographic group. It found that 27 percent of Republicans did not plan to get a shot, slightly higher than the number of independents (21 per cent), and the same as the percentage of black Americans and Americans aged 18 to 34.

Stirewalt argues that the politicians are riding a vaccine-sceptic wave rather than concocting the suspicions themselves. “It helps to think of these folks as chasing voters, viewers, money, and clicks,” he writes.

Earlier this month, Biden gave a run-of-the-mill speech on fighting vaccine hesitancy by going “community to community, neighbourhood by neighbourhood, and oftentimes, door to door — literally knocking on doors — to help to get the remaining people protected from the virus.”

Cynical opportunists are seizing on mistrust

Fed into the outrage machine, these words quickly became evidence of a sinister plot to build a vaccine Stasi. The ever-angry Republican Congresswoman, Marjorie Taylor Greene, warned against “needle Nazis”. Madison Cawthorn, another freshman GOP member of Congress, worried that if the government is going door to door to encourage vaccine uptake, “they could then go door to door to take your guns, they could then go door to door to take your Bibles”.

Cynical opportunists are seizing on mistrust. And America’s vaccine drive would be more successful were it not for them doing so. But they are only exacerbating a pre-existing problem.

The danger here is that what should be a question of gently persuading the vaccine-hesitant into getting the jab hardens into a partisan row. Coaxing can work. According to the Kaiser Family Foundation, one in four of Americans who in January said they definitely would not get vaccinated have since received at least one shot. The more polarised the vaccine question becomes, the harder persuading the unpersuaded becomes.