BUFFALO, N.Y. -- Political prognosticator James E. Campbell, professor and chair of the Department of Political Science at the University at Buffalo, predicts that the Democrats can expect to lose 51 seats in the House of Representatives in the November election, producing a Republican majority.

Campbell's forecast, to be presented this week at the Annual Meeting of the American Political Science Association in Washington, D.C., is based on what he calls the "seats-in-trouble model." This forecasting equation factors in the president's approval rating and the degree to which one political party is in danger of losing seats in the election, as estimated by the non-partisan Cook Political Report.

The paper reporting the forecast, "The Seats in Trouble Forecast of the 2010 Elections to the U.S. House," will also be published in the October issue of PS: Political Science and Politics.

"Partisanship, ideology, the midterm decline from the prior presidential surge, the partisanship of districts being defended, and even President Obama's approval ratings have set the stage for significant seat gains by Republicans in the House," Campbell writes.

In addition to examining the number of seats "in trouble" for the parties, Campbell's model examined two contextual variables.

"The first is the number of seats a party won in the previous election, which takes note of the fact that a party cannot lose seats that it does not have and cannot gain seats that it already holds," he says.

"A party registers gains first where it is easiest for it to do so," Campbell says, "and it becomes progressively more difficult for that party to pick up additional seats in areas that are more inclined to support the opposition."

He points out that in the last election Democrats took more seats than usual by winning in districts where they usually do not hold sway. This means they are "overexposed," he says, since they currently represent many districts that usually vote Republican.

He points to The Cook Report, compiled by veteran Washington analyst Charlie Cook, which handicaps congressional elections across the country, and whose past analyses Campbell calls "impressive." The report currently predicts a Republican net gain in the House of 35 to 45 seats, though it rates 68 current Democratic seats as competitive compared to only8 Republican seats. Campbell observes that the Cook Report's national projection, unlike his forecast model, does not take into account how the district ratings have been statistically related to national seat swings in previous elections.

Campbell looks as well at presidential approval ratings, which historically have a strong influence on midterm congressional elections.

"Past experience indicates that a politically neutral presidential approval rating in midterm elections is about 65 percent," Campbell says. The only two presidents to avoid midterm seat losses for their party since approval ratings have been conducted, Campbell reports, were Bill Clinton in 1998 and George W. Bush in 2002. Both enjoyed approval ratings of over 60 percent at the time of those midterm elections.

"President Obama's approval rating is now at 44 percent, however, 21 points below the neutral point," he says. "The president's ratings are not strong enough to check heavy Democratic losses this year." As a result of Democratic gains in 2006 and 2008, there are 47 Democrats sitting in districts that gave presidential vote majorities to Bush in 2004 and to McCain in 2008. Many of these are the Democratic seats now in trouble, Campbell points out.

"With these point forecasts," he says, "while there is an outside shot of Democrats holding the House, the odds appear to be quite favorable for the Republicans regaining the House majority they lost in 2006."

The author of four books, 60 book chapters and many articles in major political science journals, Campbell is president of Pi Sigma Alpha (The National Political Science Honor Society), a former American Political Science Association Congressional Fellow and a program director at the National Science Foundation. He has served on the editorial boards of six political science journals and on the executive councils of seven political science organizations.

The University at Buffalo is a premier research-intensive public university, a flagship institution in the State University of New York system and its largest and most comprehensive campus. UB's more than 28,000 students pursue their academic interests through more than 300 undergraduate, graduate and professional degree programs. Founded in 1846, the University at Buffalo is a member of the Association of American Universities.