Articles and Analysis


Abramowitz: Registered vs. Likely Voters- How Large a Gap?

Topics: 2010 Election , Generic House Vote , Likely Voters , registered voters

According to several recent national polls, Democrats may be headed toward their worst showing in a congressional election since World War II. A new NBC/Wall Street Journal Poll has Republicans leading Democrats on the generic House ballot by 9 points among likely voters while a new Washington Post/ABC News Poll has Republicans with an astonishing 13 point lead. The most recent Rasmussen weekly tracking poll has Republicans with a 12 point lead among likely voters.

If these polls prove to be accurate, Republicans could achieve their biggest popular vote margin since the 1920s. In 1946, Republicans won the national popular vote for the House of Representatives by a margin of about 9 points and that was their biggest win in the past 64 years. The Republicans' second biggest popular vote margin was 7 points in 1994.

What would such a popular vote margin mean in terms of seats? In 1946, Republicans won 246 seats in the House--a gain of 56 seats over their previous total of 190. A 12 or 13 point Republican margin would likely produce close to 260 Republican seats--a gain of about 80 seats over their current total of 179. That would be the biggest seat swing in a House election since 1932 when Republicans lost 101 seats. It would dwarf the 1994 shift when Democrats lost 52 seats, their worst showing since 1946.

It is very likely that Republicans will make substantial gains in this year's midterm election. Democrats are defending many seats in Republican-leaning districts that they picked up in 2006 and 2008, Americans are very anxious about the condition of the economy, and President Obama's approval rating has fallen into the low-to-mid 40s in recent weeks. My own forecasting model now has Republicans gaining between 40 and 50 seats in the House. But how realistic are polls that show Republicans winning the national popular vote by a double digit margin-- enough to produce record-setting Democratic losses?

There is one reason to be skeptical about some of these recent poll results--they reflect an enormous gap between the preferences of registered and likely voters. Rasmussen does not release generic ballot results for registered voters, nor do they provide any information about how they identify likely voters. But the recent NBC/Wall Street Journal Poll reported a tie on the generic ballot among registered voters. Likewise, the new Washington Post/ABC News Poll reported only a 2 point Republican advantage among registered voters.

It is not surprising that Republicans would be doing better among likely voters than among all registered voters, especially in a low turnout midterm election. Republicans generally turn out in larger numbers than Democrats because of their social characteristics and this year Republicans appear to be especially motivated to get to the polls to punish President Obama and congressional Democrats. But a double-digit gap between the preferences of registered and likely voters is unusually large.

According to data compiled by the Gallup Poll, in 13 midterm elections between 1950 and 2006 for which relevant data were available, the average gap between the preferences of registered and likely voters was 5 points. Only once, in 2002, did the gap reach double digits. In that year Democrats had a 5 point lead among registered voters but Republicans led by 6 points among likely voters. However, the gap in party preference between registered and likely voters did reach 9 points in 1962 and 8 points in both 1974 and 1982 and in every one of these years, the preferences of Gallup's likely voters were closer to the actual election margin than the preferences of registered voters. In fact, across all 13 midterm elections, the Democratic margin among likely voters differed from the actual Democratic margin in the national popular vote by an average of only 2.1 percentage points while the Democratic margin among registered voters differed from the actual Democratic margin by an average of 6.5 percentage points.

These results appear to support two conclusions. First, while a double-digit gap between the preferences of registered and likely voters is unusual, based on the history of Gallup's generic ballot polling, it is not unprecedented. Second, result of the final Gallup generic ballot among likely voters has been a very good predictor of the national popular vote for the House of Representatives. If that poll finds Republicans with a double-digit margin, Democratic losses in November could be substantially greater than those the party suffered in 1994.



Ahh, well done, professor!



Democrats lost 71 seats in 1938, 47 in 1942 and 48 in 1966. So, large losses in midterms have not been rare the last 70 years or so.



It depends on the distribution of the vote. I know liberals cite this as a defense but it is valid. Democrats won the pop. vote in 2008 by 7 pts in the House and only gained 20 pts. They garnered huge margins in safe districts and narrowly carried many red districts.

The same thing could happen to the GOP. The GOP could run up huge margins in safe south seats, steal a dozen or so D controlled House Districts and spread wins elsewhere across the US but win the pop. by say 10 pts but only gain 50 seats. The distribution of the vote is far more important than a generic ballot lead. They tie into one another but at the end of election day the distribution of the vote leads to seats.



Here is a bit of a counter message - my weekend gift to my Dem friends here:



The average RV congressional generics are not tied, but have been around GOP +5 to +6. Thus, you only need a GOP LV advantage of around 6 to 7 points to get to the Rasmussen GOP +12 results. This difference between the RV and LV numbers is high, but not remarkably so.

The RV congressional generic numbers are what is remarkable. They suggest the highest GOP lead in modern polling history by far. I am pleased to read Professor Abramowitz concur in the comparison to 1932 for the Dems and the 20s for the GOP that I have been making for a month now over at 538.com.

We may be witnessing a once in a century election.




The problem is that the Dems have a much greater degree of voter concentraion when you look at it by Congressional district.

In 2008, there were 19 districts where the GOP candidate either ran unopposed or received over 75% of the vote.

You know how many such districts there were for the Dems? 78. Including 24 where the Dem candidate ran unpposed.

Those 78 district that average 80%+ Dems do a lot more skewing than any regional factors. Yes, the GOP does better in the South, Plains States and Rocky Mountain states....but that doesn't nearly skew things as much as 78 districts like this. If the GOP has, say a 5 to 7% advantage nationwide generically, it has to be nearly double that outside these districts that were never going to be competitive anyway.




The bigger they are, the harder they fall.

Even republicans recovered from their 1928-1936 losses, from which a lot of people thought they never would, having been reduced to 88 seats in the house, truly irrelevant.

By 1942 they had 209 seats and were on track to gain back congress in 1946, which they quickly lost because they did... nothing.

But the basic point is, after having been beaten to a pulp, republicans were competitively back in the game in 6 years. They probably would have gained back congress in 1944 if FDR hadn't run for a 4th term. His popularity had been waning since 1940 anyway.

No matter how many seats republicans gain in 2010, democrats WILL be back within 10 years, probably sooner than that.



"I am pleased to read Professor Abramowitz concur in the comparison to 1932 for the Dems and the 20s for the GOP"

Republicans gained seats from 1916-1920, only to lose 77 seats in 1922. Democrats were in disarray in the mid-to-late 1920s, but they kept the house closely divided in the 1924 and 26 elections.

Then in 1928 republicans thought they had it all with a huge win under Herbert Hoover and we know how that turned out.

*recovered from their 1928-1936 losses* *correction* should have said "1930-1936."


Post a comment

Please be patient while your comment posts - sometimes it takes a minute or two. To check your comment, please wait 60 seconds and click your browser's refresh button. Note that comments with three or more hyperlinks will be held for approval.