"...there is considerable disagreement among pollsters on the magnitude of the enthusiasm gap. If Gallup’s likely voter model, which implies extremely lopsided turnout in favor Republicans, were to be correct, G.O.P. gains would be well in excess of 50 seats. "
Just to be clear, Silver says the consensus among prognosticators is that the Dems lose 50 seats, plus or minus a couple.
The big caveat is the Gallup likely voter model.
Plain and simple, if Gallup is right, the Dems are not just going to lose the House, they will lose the Senate too -- or, in the vernacular, they're toast.