Anti-vaccination sentiment is understood, in the popular imagination, to be mostly a product of Whole Foods-shopping hippies living in blue state enclaves. That’s never been entirely true, as polling data shows Republicans are a little more likely than Democrats to believe discredited claims about the dangers of vaccines, but by and large, opposition to vaccination has been a non-partisan, fringe position rejected by both parties. But that appeared to change this week as a number of prominent Republican leaders, including Chris Christie and Rand Paul, were caught openly pandering to the anti-vaccination fringe. Part of the reason was no doubt just knee-jerk hostility to pro-vaccination President Obama, but the blunt fact of the matter is that the Republican party is the natural home for anti-vaccination conspiracy theories. Here’s the four major reasons why.

Republicans are already warm to anti-science conspiracy theories. Anti-vaccination advocates are, at their core, conspiracy theorists. You’d have to be in order to believe that all major health organizations in the world are colluding to cover up the supposed dangers of vaccines and that only a few non-scientists on the internet have access to the truth. The anti-vaccination conspiracy theory resembles nothing so much as the widespread right wing conspiracy theory, endorsed by most Republican leaders, that holds that the vast majority of climate scientists worldwide are colluding to hoodwink the world about the realities of global warming.

In both cases, the conspiracy theories don’t even make sense on their own terms. Anti-vaxxers argue that the conspiracy to conceal the supposed truth about vaccines is done to preserve Big Pharma profits, which makes no sense as vaccines are not profitable. (In fact, they make pharmaceutical companies so little money the real problem is convincing them to keep making them.) Similarly, global warming conspiracy theorists would have you believe climate scientists are lying to tap into an imaginary cash flow of anti-oil industry money, when in reality the opposite is true: The oil industry is pouring millions of dollars into propping up the lie that global warming is not a real thing.

Republicans are already practiced at spreading lies about health care. Through the anti-choice movement, Republicans have become adept at spreading lies and misinformation about basic health care practices. They lie about emergency contraception, claiming it’s “abortion” when it actually works by preventing pregnancy. They lie about abortion, claiming it’s dangerous and needs all these extra regulations (that just so happen to put safe, legal clinics out of business), when in fact abortion is one of the safest outpatient procedures you can get. They claim abortion causes breast cancer and mental illness, both of which are not true. They claim that birth control is so cheap women don’t need health insurance coverage of it, which is a lie. They claim fetuses can feel pain at 20 weeks, another lie. Republicans have perfected the art of lying about women’s health care, so moving on to lying about children’s health care is a natural transition. Hell, one reason so many conservatives oppose reproductive health care is it’s seen as impure and unnatural, which is exactly what anti-vaxxers say about vaccines.

In fact, there’s even some overlap. For years now, conservatives have been fighting against one particular vaccine, the HPV vaccine that prevents a disease that causes cancer and is primarily transmitted sexually. As with conservative opposition to abortion and contraception, opposition to the HPV vaccine is rooted in the erroneous idea that you can bully women out of having sex by depriving them of basic sexual health care. The anti-HPV vaccine campaign has already been a much bigger success than all other anti-vaccine campaigns combined. Over 40% of teen girls who need the vaccine have not gotten it. And that’s just one vaccine! Imagine the damage they could do if they commit to sowing doubts about other vaccines.

Republicans already support giving parents broad rights to mistreat their children. Justifying his opposition to mandatory vaccination, Rand Paul said,” The state doesn't own your children. Parents own the children.” It’s not true (sense a theme here?), as the constitution explicitly forbids any human being owning another, with no exceptions made for children. But sadly, Paul was speaking for a widespread belief on the right that parents should be treated less as guardians for children and more like owners. It’s one reason that conservatives are forever trying to undermine public schooling and, when they can’t do that, trying to remove the ability of schools to teach facts that parents want to shield kids from. Particularly on the Christian right, there’s a lot of hostility to the idea that children are people with rights instead of property. The reason the U.S. hasn’t ratified the UN Convention on the Rights of the Child when nearly all countries elsewise in the world have is because conservatives are afraid that it might limit their ability to beat children or force religious beliefs on unwilling children. Any attempt to put limits on how badly you can treat your children, from bans on forcing gay children into discredited “pray the gay away” programs to limits put on homeschooling, is bound to be met with opposition by conservatives who think we should treat children like property instead of people.

Demanding the right to expose your children to contagious and even deadly diseases for your half-baked “principles” fits right into the existing conservative mindset, clearly.

Republicans are already hostile to the idea of the common good, particularly when it comes to health care. The ongoing battle over the Affordable Care Act really goes back to one basic principle, which is that Republicans reject the idea of universal health care. At its core, hostility to universal health care is rooted in the deep classism of the right: They don’t want to share their neighborhoods, schools, or churches with lower class people, so of course they don’t want to share the medical system. That’s why myths about “waiting lists” and “death panels” persist despite the evidence: It’s a way to suggest that letting poor people into the health care system is going to ruin it for everyone. Even if that means people die unnecessarily, conservatives will demand that we maintain that separation between the rich and the poor, even on something as basic as health care.

Similarly, anti-vaccination advocacy is primarily an affectation of upper middle class and wealthy Americans who aren’t exactly subtle about their disdain about having to subject their children to the same tawdry needle-based healthcare that poor people get. “My child is pure,” Dr. Jack Wolfson, anti-vaccination advocate, told CNN. “It’s not my responsibility to be protecting their child.” Anti-vaxxers often highlight how they’ve replaced boring old vaccines with expensive alternatives, such as organic foods. It doesn’t matter, really, that vaccines actually work whereas there’s no evidence that expensive organic foods do squat. The only thing that really matters is making a distinction between elite health care and common people health care—and refusing to participate in the latter. This mentality sits quite nicely with Republican opposition to universal healthcare, which is so clearly rooted in the fear of having to share resources with lower class people.

At its core, the anti-vaccination movement has always been a reactionary one: Hostile to poor people, obsessed with the conservative myth about bodily “purity,” hostile to the expertise of scientists and doctors. Because of that, its drift into just another obsession of our increasingly nutty right wing was inevitable. The polling data is also beginning to show this, as recent years have shown Democratic support for mandatory vaccination rising while Republican support is falling. Despite having started in “blue” areas, anti-vaccination is the inevitable result of conservative rejection of the idea of collective responsibility, particularly their attacks on public schools and universal health care. Which is why this is all happening.