The U.S. Congress will see a steep drop in Jewish members after the November election, a Forward analysis suggests.

The Forward is projecting that 31 Jews will serve in the next Congress — eight fewer than the number that served at the start of the last Congress.

Interactive map of 2012 Congressional elections involving Jews

In the House, if current trends hold, 21 Jews are likely to be elected this November, seven fewer than were elected in 2010. The projected drop in the Senate is less precipitous. The Forward expects 10 Jews to be serving there next year. Twelve currently serve.

Click on map or here to see each projections for each Jewish candidate.

If the projections hold true, the percentage of members of the House and Senate who are Jewish will be lower than it has been in decades.

The projected figures are based on subjective judgments about the outcome of a handful of contested races. Those judgments could change as the election nears. They also don’t include three races — two in the House and one in the Senate — that the Forward considers toss-ups between a Jewish and a non-Jewish candidate.

The Forward projects that 31 members of the House and Senate will be Jewish in 2013. The last Congress with so few Jews entered service in 1979, according to data presented by the Pew Forum on Religion & Public Life. The Jewish membership of the current, 112th, Congress is 7.3%.

Jews are estimated to make up roughly 2% of the U.S. population.

It’s not clear what these projected changes mean — or if they mean anything. “There’s no way to say what’s statistically significant or not,” said Alan Cooperman, associate director for research at the Pew Forum. Still, Cooperman said, there seems to have been a clear trend of growth of Jews in Congress from the 1970s to the 2008 election. The 111th Congress, which served from 2009 to 2011, was 8.4% Jewish — an apparent peak.

If the Forward’s projections are correct, the 2012 election could erase those gains.

Some experts say the projected decline could be related to general population shifts away from the Northeastern states where Jews have long been concentrated. That broad trend has resulted in states that have large Jewish populations — New York, New Jersey, Pennsylvania and Massachusetts — losing seats, while Arizona, Utah and South Carolina are gaining.

Even when Jews move South and West, they don’t play the dominant role they played back East. “The places where Jews are now living are more, in general, competitive,” said Kenneth Wald, a professor of political science at the University of Florida. Despite growing numbers of Jews in Arizona, for example, there are no so-called Jewish seats there, as there are in places like Brooklyn.

On the other hand, a difference of nine individual legislators between January 2011 and January 2013 may not mean much.

Some of the drop in Jewish legislators is due to fluke incidents and retirements. House Democrats Anthony Weiner and Gabrielle Giffords have both left the House since the last election for very different, high-profile reasons: Weiner because of a sexting scandal, and Giffords because of injuries suffered during an assassination attempt. Long-serving Boston Democratic Rep. Barney Frank decided to retire, as did long-serving Queens Rep. Gary Ackerman. In the Senate, Wisconsin Democrat Herb Kohl and Connecticut Independent Joe Lieberman are both stepping aside after lengthy careers.

Other losses are directly attributable to the redistricting process, which has redrawn congressional districts across the country since the last election. Incumbent California Jewish Democratic Reps. Howard Berman and Brad Sherman are competing to represent the same district in November. Steve Rothman, a New Jersey Democrat, lost a primary race against another Democratic incumbent.

Whatever the drop in Jewish congressmen means, it’s likely not a sign of a change in how Americans feel about Jews. “It’s still the case that Jews will be statistically overrepresented to a considerable degree,” Wald said.

Contact Josh Nathan-Kazis at nathankazis@forward.com or on Twitter @joshnathankazis