Is there any evidence that conservatives stayed home? I don't know any who did. Further, I don't know any conservatives that voted for Democrats as a "revenge" vote.
What I saw was that the Republicans lost the middle so called swing voters on the war and immigration.
In either case, the collective "we" conservatives did it to ourselves.
I wish it *had* been due to principled conservatives staying home. If so, the party might actually have to move right in order to regain their votes. But since it was the swing voters we lost, the party bigwigs will simply continue drifting leftward in a vain attempt to out-Dem the Dems.