Have We Underestimated GOP Wave: Political Prognosticators were off by half in '94. Are they off by half now?

Polls showing HUGE gap favoring GOP in generic ballot don't match polls for individual races. Which is right?

First off, let's not get too excited. We've been waiting two years for this moment and we may be in for a long night before many of these races are decided. But there's a nagging sense, or perhaps just a fervent hope, that the wave we know is coming will be bigger than almost anyone has predicted.

You can't help looking at the historic highs currently reported in favor of the GOP for the generic ballot and wonder if maybe the predictions on the number of House seats and Senate seats is low. Match that wonderment with the predictions of top prognosticators in 1994:

• Charles Cook, editor and publisher of the Cook Political Report:"The Democrats will lose 20-25 in the House; four to five in the Senate.

• Stuart Rothenberg, editor and publisher of the Rothenberg Report, a political newsletter: "The Democrats will lose 24-26 seats in the House; three to five in the Senate.

• Larry Sabato, professor of government at the University of Virginia: it looks like Democrats will be lucky to lose only 24-25 seats in the House and four in the Senate.

In 1994 nearly every expert was WRONG and pegged GOP House gains at less than HALF what they turned out to be (54). Many of these same experts are now putting the GOP gain this year at 47-55 seats. It's unlikely that the actual result will be close to double those numbers, but it's not impossible either.

Jay Cost, writing at the Weekly Standard applies the generic ballot data to a model he uses to predict results based on past performance of that and other variables and comes up with this prediction:

Frankly, my gut tells me that Gallup’s R +15 is too high, but then again I think the ABC News/Washington Post poll (R+4) is wider off the mark than Gallup. Mark Blumenthal has noted that there is no real middle in the final generic ballot numbers. They are all either high or low. I’m going high because of the metric’s historic tendency to undercount Republican strength. And while Gallup may be higher than normal this year, it is still the smart bet that Gallup is on the correct side of the ledger.

Thus, my intuition is that the final result will be a Republican share of the two-party popular vote of about 55 percent, with 45 percent going to the Democrats. That may seem like a big margin, but it is not far from 1994 when the Republicans won 53.5 percent of the two-party vote and the Democrats won 46.5 percent. Also, it tracks very closely to Ronald Reagan’s share of the two-party vote in 1980 (55.3 percent).
How many seats will this produce? Again, it’s exceedingly difficult to say. My model suggests a pickup of about 75 seats, give or take.

Writing at Hot Air, Daffyd Ab Hugh calculates the "win factor" (a combination of House and Senate seat gains) and comes up with the following chart of biggest wins in the 20th Century:

Here are the top five post-War historical benchmarks in countdown order, based on win-factor:
5.1974 mid-terms: Democrats gain 49 House seats and 3 Senate seats; win-factor = 62.1
4.1994 mid-terms: Republicans gain 54 House seats and 8 Senate seats; win-factor = 88.8
3.1946 mid-terms: Republicans gain 55 House seats and 12 Senate seats; win-factor = 107.2
2.1948 presidential: Democrats gain 75 House seats and 9 Senate seats; win-factor = 114.2
1.1958 mid-terms: Democrats gain 49 House seats and 16 Senate seats; win-factor = 118.6

(1958 was kind of an oddball election; it’s only number one because of the enormous pickup in the Senate.)

So what would it take for this election to grab the top spot, the biggest pickup of the entire post-War era? Here are a few examples; for each number of Senate pickups, I list the minimum number of House seats to break the 1958 record:

•8 Senate seats and 84 House seats (win-factor = 118.8)
•9 Senate seats and 80 House seats (win-factor = 119.2)
•10 Senate seats and 76 House seats (win-factor = 119.5)
•11 Senate seats and 71 House seats (win-factor = 118.9)
•12 Senate seats and 67 House seats (win-factor = 119.2)

Shortly we will know how large in historical terms this election ranks. Speaking personally, it already feels historic! No matter what, tonight will be a great night for Liberty and Freedom! Either way, AMERICA WINS!