So here's what Novak's "largest tax increase in U.S. history" actually comes to: the Republicans passed a series of tax cuts that they set up to expire. They intended to make them permanent, but never got around to it. The Democrats are proposing to leave their tax cuts alone. But this counts as a tax increase, apparently on the grounds that whatever Republicans sorta kinda thought they were going to do, but never actually got around to doing, counts as already done, and anyone who proposes to leave things alone counts as undoing the things they were intending to do.
The rest of the equation is worth reading.