Wait a second, how can you claim that democrats "failed" to strike when the iron was hot? They made major gains in the reddest districts in the house. Literally, these have been republican strongholds for over 20 years.
Please explain how losing 15-25 pts in 6 months isn't alarming for republicans sitting in far more moderate and competitive districts?
I don't think what you're saying follows.
Just like in a basketball game where your team is down 20 at halftime. The final score has your team lose by 5pts and you claim that you "won" the second half. It doesn't work like that. Since wins and losses are all or nothing, the other team just has to win. Winning by 20% or 5% doesn't change the outcome. So if you're able to easily win by 5% you'll take that all day every day and there is no need to spend more or to try to include more voters so that you can win by 20%. You just go ahead and take the 5% win and move on.