Back in August, a half dozen of the GOP presidential candidates dutifully showed up for an Iowa forum on education reform to present their plans on the issue to the voters. A similar event is scheduled for the Democrats this month. Or perhaps I should say that it was scheduled. The event is now pretty much canceled because not one of the Democrats running for the White House was willing to show up.

Democratic presidential candidates are blowing off an education forum that anchorwoman-turned-activist Campbell Brown was expected to host in Iowa this month, and Brown blames pressure from traditionally Democratic teachers unions eager to move the party away from President Barack Obama’s school reforms.

In August, six Republican candidates appeared at a New Hampshire forum sponsored by Brown’s education reform news site, The Seventy Four, along with the school choice advocacy group the American Federation for Children. Those groups had announced a similar October event for Democrats in conjunction with the Des Moines Register, but the former CNN anchor said that none of the candidates would commit to attend even in principle before last week’s deadline, and that operatives from several campaigns told her privately that the unions had urged them to stay away.

There is absolutely zero mystery as to what’s going on here. There’s no problem with the topic because Democrats simply love talking about education. It’s been one of the highlights of every campaign in recent memory, including both of Barack Obama’s runs. The real poison pills which doomed this opportunity for Iowa voters to get to know the positions of the candidates better were the name of the host and iron clad grip of the teachers unions on the party.

The event, like the GOP gathering in August, was to be hosted by Campbell Brown. You might think she would be a natural fit for such a Democrat events since she was born and raised in a Louisiana Democrat family and was a former CNN anchor. (Yes, she’s married to Dan Senor, but the heart wants what the heart wants. Such mixed political marriages are actually quite common.) She’s also been a an unflagging fighter for reforming the nation’s broken public school system, though, and that makes her persona non grata with the unions who finance most of the Democrats’ campaigns. As such, union bosses turned the screws and Hillary Clinton, Bernie Sanders and Martin O’Malley all turned tail and slunk away.

What sort of resolve to principles does this demonstrate? Are they all truly this terrified of the physically diminutive Brown and her “radical” ideas about charter schools, vouchers and teacher rating systems? Nobody was saying that they had to come and endorse her agenda. They could have shown up and argued in favor of the status quo all they liked, pushing tenure, higher taxes and no accountability for school performance. In some ways that might have actually improved their chances of an endorsement from the unions. But instead they were given their marching orders from the forces who follow Randi Weingarten and they shut down the event entirely.

Bravery, thy name is Democrats. Just look for the union label.