More from the analysis ...

... Even as this year's election results have left many in the party encouraged they can mount a massive blue wave, next year's battleground is a far cry from 2018 -- with fewer Republican-held seats for Democrats to easily target.

Democrats don't need to win as many seats this time around, netting just three seats rather than two dozen to claim a majority. But the hill to reach a comfortable majority like the 235 seats they held after the last blue wave has grown much steeper, driven by multiple rounds of gerrymandering -- including ongoing redistricting in several states that threatens to erode the battlefield even further.

The result is that Democrats could post a bigger national swing than in 2018 and still end up with a slimmer majority than they had after that year. To flip 40 seats again would require them to win not just the kinds of highly competitive seats that fueled their House takeover last time but every district that Trump won by 12 points or less, a task that would not only defy political gravity but upend it. ...