[The Great Yazoo]

And it wouldn't just be a matter of demanding that historians play down the role of slavery in early America

What conservative demands historians "play down the role of slavery?" I know of no slavery-deniers in the conservative movement, only those who plead for balance, context, and fairness in dealing with slavery. Nor do I know any conservative suggesting, no matter how remotely, that slavery wasn't wrong.

[Smokin' Joe]

What! You haven't heard? There is no way that (one) Rich Whiteman guy could have built this country without all those slaves.../Sarcasm

Yep, the slaves did a lot of work, but so did the rest, and giving them credit, too is not 'downplaying' the role of slavery, just giving credit to all who deserve it.