Childhood vaccines have become a highly partisan issue in Oregon. The "vaccine choice" movement is now all but a plank of the Oregon Republican Party.

House Bill 3063 advanced from committee on a party-line vote, with seven Democrats in support and four Republicans opposed. On the floor of the Legislature, a similar pattern is expected—with a few dissenters, including two Republican sponsors.

Former state Rep. Knute Buehler (R-Bend), an orthopedic surgeon, opposed requiring vaccines in his failed run for governor last year. Jonathan Lockwood, a spokesman for three Republican legislators, stood watching and lending support at a Capitol protest last week where anti-vaxx parents sang the national anthem.

And in committee, Rep. Ron Noble (R-McMinnville), a retired police chief, channeled the anti-vaxxer movement when he talked about how there are smart people on both sides.

"We have experts that say we need to vaccinate," said Noble. "We have experts that say we get injured. We have experts that say we don't get injured and experts that say we need to expand on medical exemptions. I've learned a whole lot. The unfortunate part is, experts are on both sides, so I've had to do some of my own research."

That last saying—"I've had to do my own research"—is practically a motto of how misinformation is spread about vaccines and how fake news travels more generally in the internet age.

Part of the reason for GOP opposition is religious freedom. "It's a Republican-Democrat issue, but not in the way we often think of it," says Rep. Rob Nosse (D-Portland). "It gets at some very core principles for Republicans. In a state that is very unchurched, the right to worship is felt very strongly among Republicans, even among Republicans who believe in vaccines. It's a tough issue for them."

Former state Rep. Julie Parrish (R-West Linn), says parents with religious objections to vaccines could mount a legal challenge to any requirement they get their kids vaccinated.

"There is a shot to sue," she says.

Walking through the hallway to sing the national anthem, one protester called out that she was changing her voter registration to Republican.

Dr. Paul Thomas sympathizes.

"I've been a Democrat my whole life," Thomas says. "It felt like the Democrats stood up for the little guy." But Republicans, starting with President Donald Trump, have embraced the anti-vaccine agenda: "I mean, I would love [Trump] if he could just fix this vaccine thing."