PRINCETON, NJ -- Gallup tracking of 2010 midterm congressional election voting preferences shows 47% of registered voters saying they would vote for the Republican candidate and 44% for the Democratic candidate if the election were held today. Though down slightly from last week's seven-percentage-point Republican lead, the GOP has held an advantage each of the past four weeks, the first time either party has done so this year.
The consistent Republican advantages are also notable from a historical perspective. In Gallup's 60-year history of asking the generic ballot question, it is rare for the Republicans to be ahead among all registered voters. In fact, last week's seven-point lead is the largest Gallup has measured for the Republican Party at any point in a midterm election year.
Even in two of the strongest Republican years -- 1994 and 2002 -- Democrats led or were tied in the final pre-election poll among registered voters. Republicans, however, led in those polls once turnout was factored in using Gallup's likely voter model, which correctly forecasted that more voters would cast ballots for Republican than Democratic candidates. (Gallup will begin to provide likely voter estimates for the 2010 vote in October.)
Republicans usually make gains in their share of the vote after the likely voter model is applied, and generally hold an advantage in actual voter turnout in midterm elections, so a Republican advantage among all registered voters is an ominous sign for the Democrats' prospects.
There are signs voter turnout in 2010 is not likely to go against historical patterns, with 46% of Republicans and 23% of Democrats saying they are "very enthusiastic" about voting this year. Republicans have led in reported enthusiasm throughout the year, and the current figures are tied for the largest enthusiasm gap by party this year.
Republicans' relatively stronger showing on the generic ballot throughout August is due in part to Republican gains in party affiliation and a slightly higher level of support for Republican candidates among independent voters, as detailed in last week's update.
In addition, though party loyalty in terms of voting is high on both sides, in August there are signs of slight but notable changes. So far this month, 96% of Republican registered voters say they would vote for the Republican candidate, exceeding Republicans' party loyalty for any prior month. At the same time, the percentage of Democratic registered voters preferring the Democratic candidate -- 91% -- matches the monthly low for either party to date.
Gallup's generic ballot for Congress, which has been an accurate predictor of the national vote for the U.S. House in past midterm elections, continues to suggest 2010 will be a good year for the Republicans. The consistent Republican advantages among all registered voters in recent weeks are unusual from a historical perspective. Though a swing in the Democratic Party's favor cannot be ruled out, voting patterns observed in the generic ballot in a given midterm election year generally hold throughout that year.
Explore more Gallup data relating to the upcoming congressional midterm elections, including Gallup's complete generic ballot trend since 1950 in our Election 2010 key indicators interactive.
Results are based on telephone interviews conducted as part of Gallup Daily tracking survey Aug. 16-22, 2010, with a random sample of 1,577 registered voters, aged 18 and older, living in all 50 U.S. states and the District of Columbia, selected using random-digit-dial sampling.
For results based on the total sample of registered voters, one can say with 95% confidence that the maximum margin of sampling error is ±3 percentage points.
Interviews are conducted with respondents on landline telephones and cellular phones, with interviews conducted in Spanish for respondents who are primarily Spanish-speaking. Each daily sample includes a minimum quota of 150 cell phone respondents and 850 landline respondents, with additional minimum quotas among landline respondents for gender within region. Landline respondents are chosen at random within each household on the basis of which member had the most recent birthday.
Samples are weighted by gender, age, race, Hispanic ethnicity, education, region, adults in the household, cell phone-only status, cell phone-mostly status, and phone lines. Demographic weighting targets are based on the March 2009 Current Population Survey figures for the aged 18 and older non-institutionalized population living in U.S. telephone households. All reported margins of sampling error include the computed design effects for weighting and sample design.
In addition to sampling error, question wording and practical difficulties in conducting surveys can introduce error or bias into the findings of public opinion polls.
For more details on Gallup's polling methodology, visit www.gallup.com.