"I know how important control of the House is"
Absolutely correct.
There will be a complete STALEMATE in the House. Nothing will actually get done about any of the SWAMP in the House because the minute they are threatened, the Dems will be in a position to order even more Investigations, create even more Fake Accusations and DELAY absolutely everything until 2020.
How long has the Mueller investigation gone on for SO FAR ? 2 years + ? .
The House Speaker in NOT a key post.
The post that will CAUSE most problems for the GOP is in the Intelligence Committee. If Schiff takes the Chairman spot in the Intelligence panel, which was headed by Trump protector Devin Nunes, it may result in NEW Special Counsels being appointed to investigate all kinds of things. These NEW investigations will be even worse than the Mueller Russia investigation and last longer. Their purpose will simply be to SMEAR Trump.
MORE and MORE Witch Hunts.