The Koch brothers' political network is rolling out new ads Thursday targeting both Democrats and Republicans over tax reform, including pressuring Republicans to ditch the border adjustment tax (B.A.T.) favored by Paul Ryan. The digital ads are part of a previously announced, multi-million Koch network campaign to promote tax reform.

The targets: Republicans on the tax-writing House Ways and Means Committee (to "drop the B.A.T.") and nine Democratic senators — including moderates like Joe Manchin and Heidi Heitkamp (to "support tax reform").

Why it matters: The Koch network is the best-funded conservative network in the country, and they've got the resources — including a massive grassroots army — to sway members. They've already played a key role in making the border adjustment tax politically toxic, and now they want to arrange its funeral and move on with the rest of Trump's tax agenda.