Democrats in Stronger Position Than GOP to Make Gains in US House in 2010

Although history tells us it is a rarity for the party in control of the White House to make gains in congressional seats during mid-term election years, all the numbers from the 2008 elections point to the Democratic Party to remain in a very competitive position to add to their large advantage in the U.S. House in 2010.

During the past 100+ years, there have only been four instances in which the party controlling the White House has picked up seats in the U.S. House during the mid-term cycle. However, two of these cases have occurred during the past decade: 1902, 1934, 1998, and 2002.

So why would 2010 defy this general historical trend? There are several key factors:

First, the Democratic margin of victory across the 435 House races in 2008 was a whopping 16 points higher than that of the GOP. Democrats won by an average margin of 44.7 points compared to just 28.7 points for the Republicans. Since redistricting in 2002, the average Democratic margin of victory has been remarkably stable – hovering between 44 and 45 points. The average Republican victory margin, however, has been quite volatile: dropping from 41.2 points in 2002, to 37.2 points in 2004, to 25.3 points in 2006, before rebounding a bit in 2008.

Average Margin of Victory in U.S. House Elections, 2002-2008

Year	Democratic MoV	Republican MoV
2008	44.7	28.7
2006	45.8	25.3
2004	44.6	37.2
2002	44.2	41.2

Source: data compiled by Smart Politics.

Still, considering the Democrats netted 30 seats in 2006 and 21 seats in 2008, this large Democratic margin of victory is truly remarkable. With Democrats winning 257 seats to the GOP’s 178 in 2008, one would expect those Republicans who were victorious to be winning larger, more lopsided victories in heavily red districts. Similarly, one would expect a larger number of Democratic seats to be more closely decided than GOP seats – with the Democrats picking up a number of swing districts and right-leaning districts.

But this hasn’t been the case.

In both 2006 and 2008, despite the Democratic Party winning more than 50 swing seats, Republicans nonetheless won more competitive races, those decided by less than 10 points, than the Democrats: 30 to 28 in 2006 and 26 to 24 in 2008.

Number of Competitive U.S. House Seats Won by Party, 2002-2008

Year	Democratic seats	Republican seats
2008	24	26
2006	28	30
2004	10	10
2002	18	15

Note: Denotes races decided by less than 10 points. Data compiled by Smart Politics.

And there is more bad news for the GOP: in 2010 the Republicans will also have to defend more ‘near competitive’ districts (those decided by 10 to 19 points) and ‘marginal’ districts (those decided by 20 to 29 points) than do the Democrats. In 2008, the GOP won 39 seats decided by between 10 and 19 points, compared to 34 seats for the Democrats, and won 53 seats decided by between 20 and 29 points, compared to just 29 seats for the Democrats.

In sum, when 2010 comes along, the GOP will be forced to defend 36 percent more competitive, near competitive, and marginal districts (118) than will the Democrats (87).

This built-in advantage for the Democrats may be enough to ward off the historical loss of seats that usually occurs during mid-terms. However, with Democrats quickly pushing their controversial stimulus bill through Congress during Obama’s first three weeks in office, the ultimate determinate of Democratic gains or losses in 2010 could likely be the ultimate (perceived) success or failure of that singular piece of legislation. Republicans, who voted unanimously to oppose the bill in the House, no doubt now have a unified message and strong issue to run on in 2010 should it fail.

One further note: an additional reason Democrats have been able to maintain a much larger average margin of victory than Republicans during the last two election cycles - even as they picked off more than 4-dozen seats - is because:

a) they have reduced the number of districts in which they failed to run a candidate by 70 percent, from 80 districts in 2002-2004 to just 24 districts in 2006-2008, and

b) the number of districts in which the GOP has failed to run a candidate has increased 32 percent – from 66 districts in 2002-2004 to 87 districts in 2006-2008.

U.S. House Districts in Which Major Party Fails to Field a Candidate, 2002-2008