[cnn-photo-caption image= http://i2.cdn.turner.com/cnn/2010/images/07/12/art.capitolbldg.file7.gi.jpg caption =" The latest generic ballot from Gallup indicates that Republicans are 10 points ahead of the Democrats."]Washington (CNN) - In the battle for control of Congress, the generic ballot is arguably the most watched polling indicator. And thanks to the latest generic ballot from Gallup that indicates the Republicans 10 points ahead of the Democrats, the indicator is getting a lot of buzz.
So what is it and is it a reliable barometer of what may happen on election day?
The generic ballot question asks respondents if they would vote for a Democrat or Republican in their congressional district, without naming any specific candidates. It's used by many polling organization, including CNN/Opinion Research Corporation surveys.
According to the generic ballot from the Gallup Daily Tracking poll that was released Monday, 51 percent of registered voters said they would support the unnamed GOP candidate with 41 percent saying they would back the Democrat in the race. The numbers mark the fifth straight week the Republicans have held an advantage on the question and is the party's largest lead ever in midterm contests in Gallup's polling history.
So where does the race stand in other generic ballot surveys out this month. A Newsweek poll has both parties deadlocked at 45 percent, the GOP's up by one point in an Ipsos/Reuters survey, the Republicans hold a seven point lead in Time poll, the GOP has a four point advantage in an AP-GfK survey, the Republicans are up seven points in a FOX News/Opinion Dynamics poll, and they hold a three point advantage in a CNN/Opinion Research Corporation survey.
Average all those polls together and you find the GOP with a single digit lead, virtually the same position they held at the same time in 1994. That November the Republicans grabbed 54 seats back from the Democrats, winning control of the House of Representatives. They also captured the Senate.
The Democrats also held a similar lead in generic ballot polling at this point in 2006, just before they won back control of both chambers of Congress.
But the generic ballot should not be considered one-stop shopping.
"The problem with interpreting the generic ballot is that a national poll cannot produce the same results that 435 separate polls in 435 House districts would produce," says CNN Polling Director Keating Holland.
"No one has the budget to do a significant number of telephone interviews in every House district in the country, so the generic ballot has become a proxy for that. But it can produce odd results if, by the luck of the draw, your national sample happened to get a lot of highly-Republican or highly-Democratic districts. That's why analysts tend to look at other measures as well."
Among the indicators to look at once the campaigns heat up after Labor Day are the favorable ratings on the two parties, questions about which party should control Congress, ratings of the parties on major issues, and the president's approval rating.
"Some academic experts have done a good job forecasting the results of midterm elections with statistical models that pay little or no attention to the generic ballot," Holland says. "But if you're looking for just one number that tries to forecast what will happen in 435 different House races, the generic ballot is usually the one most analysts focus on."
Follow Paul Steinhauser on Twitter: @psteinhausercnn