50+ seat gain for the GOP in the House? It's very possible.

Just a few months ago, a takeover of the U.S. House seemed like a near impossibility.

And now it's inching ever closer to the "likely" category. And it's not even a Republican saying so.

Nate Silver, one of the best poll analysts the Democrats have on their side, recently laid it out for us:

...if the House popular vote were exactly tied, we'd expect the Democrats to lose "only" 30 seats on average, which would be enough for them to retain majority control. It would take about a 2.5 point loss in the popular vote for them to be as likely as not to lose control of the chamber. So Democrats probably do have a bit of a cushion: this is the good news for them.

Their bad news is that the House popular vote (a tabulation of the actual votes all around the country) and the generic ballot (an abstraction in the form of a poll) are not the same thing -- and the difference usually tends to work to Democrats' detriment. Although analysts debate the precise magnitude of the difference, on average the generic ballot has overestimated the Democrats' performance in the popular vote by 3.4 points since 1992. If the pattern holds, that means that a 2.3-point deficit in generic ballot polls would translate to a 5.7 point deficit in the popular vote -- which works out to a loss of 51 seats, according to our regression model.

The above-named 2.3% deficit is per the RCP average.

Democrats, want to think of something scary?

And what if, for example, the Rasmussen case comes into being? Rasmussen has the Democrats losing the generic ballot by 9 points (and has had similar numbers for awhile). A 9-point loss in the House popular vote would translate into a projected 65-seat loss for Democrats. Or, if we adjust the Rasmussen poll to account for the fact that the Democrats' performance in the popular vote tends to lag the generic ballot, it works out to a 12.4-point loss in the popular vote, which implies a loss of 79 seats!

Now we all expect the generic poll numbers to fluctuate between now and November, but if they end up in the 2.3% margin that Silver analyzed, watch out.