The Blue Wave Rises, Con't

Nate Silver reminds us that predictions of Democrats taking the House (and Republicans keeping the Senate) are only as good as the accuracy of state-level polling, and the accuracy of state-level polling is only as good as the likely voter models in those polls. In 2014, 2015 and 2016, state-level polling underestimated Republican turnout because likely voter models were wrong, especially here in the Midwest.

The forecasts are in, and they say the 2018 elections can go any number of ways.

If you’re following election coverage and forecasting models, you know the conventional wisdom at this point: Democrats are the favorites to take the House, and Republicans are the favorites to hold on to the Senate.

FiveThirtyEight’s “classic” forecast — which has become the gold standard in elections forecasting — gives Democrats an 85.6 percent chance of retaking the House and Republicans a 81.3 percent chance of holding the Senate, as of Tuesday evening.

So both of those are highly likely to happen, right?

Well, one person who’s been trying to complicate that assessment is FiveThirtyEight founder Nate Silver himself.

One point Silver has made over and over again in recent weeks is that even if you take his House and Senate forecasts at face value, when you think about both of them together, there’s around a 40 percent chance that one of them will be wrong.

He elaborated on this on Twitter this week, making a point that’s important to understand — that a “very normal-sized polling error” in either direction could result in a dramatically different outcome.

If polls underestimate Republicans by 2-3 points—which is a very normal-sized polling error—the House is a district-by-district nail-biter.

If polls underestimate Dems by 2-3 points, their path to victory in the Senate is much more viable; toss-ups go their way, TN/TX close etc.

— Nate Silver (@NateSilver538) October 22, 2018

That's a major issue.  If those state-level polls are once again underestimating Republican turnout as "likely voters" by 2-3 points, then a lot of those 29 GOP tossups I talked about yesterday become Republican leaners and the proposition of the Dems taking half of those tossups and the House becomes Republicans defending the vast majority of those seats and limiting their losses to 15-20.

In the Senate, that means that Republicans defend Nevada and Arizona and pick up North Dakota, but it also means they pick up Indiana, Missouri, Florida, Montana and maybe, just maybe New Jersey, one of Minnesota's seats (Tina Smith's), and Joe Manchin, Tammy Duckworth, and Debbie Stabenow have very, very long nights.

On the other hand, if this goes in the other direction, then yes, we see the Blue Wave scenario where Democrats pick up 40-50 seats and maybe more, and in the Senate, Dems defend nearly all of their Trump state seats and pick up Nevada and Arizona, and maybe even Tennessee and dare I say it, Beto slays a troll in Texas, and suddenly Dems have 51 or 52 in the upper chamber to go with it.

So yeah, I take Nate at his word when he says there's a decent chance one party takes Congress.

We should vote like we have that chance.  Early voting started in Florida on Monday and continues.

Arkansas, Alaska, Idaho, Massachusetts and Texas also opened their polls for early voting Monday. They will be followed by Hawaii, Louisiana and Utah on Tuesday; West Virginia on Wednesday; Maryland Thursday and the District of Columbia Friday.

Kansas and Oklahoma will start early voting next week.

A large swath of states -- including Arizona, California, Georgia, Virginia, Minnesota, New Jersey, North Carolina, Ohio, South Carolina, South Dakota, and Tennessee -- have been voting early for weeks.

The time to cast your early vote in these states is now.  Do it today if you can.