ROANOKE, Va. - It may seem an unlikely source for political prognostication, but a Virginia liberal arts school's choice for the Democratic presidential nominee may be the bellwether in this year of unpredictability.

That's because Washington & Lee University's mock convention has a history of getting it right. It has picked the correct presidential nominee for the party out of power every time but once since 1948.

Students choose their nominee from painstaking research in all 50 states, and they are being especially diligent this year as the private school in Lexington celebrates the 100th anniversary of its convention, spokeswoman Eugina Huang said.

"We have to make a very studied and risky decision on Jan. 26 because the race is just literally a crapshoot right now," said Logan Gibson, head of the committee that lined up convention speakers.

The W&L students got their first two predictions this year wrong: Hillary Clinton as the winner of the Iowa caucuses and Barack Obama in the New Hampshire primary. Voter polls and pundits also had picked Obama to win in New Hampshire after his victory in Iowa.

"We were discouraged a little bit by having those wrong," said Huang, a junior. In response the students have stepped up their research in other states, which includes interviews with political leaders.

A network of politically connected W&L alumni helps make the convention successful, Gibson said. Alumni help find speakers, as well as direct students to knowledgeable sources of information about where the candidates stand across the country.

The two-day convention offers all the placard-waving, balloon-releasing hoopla of the real thing, and organizers seek to include the party's rising stars among their speakers. Past gatherings attracted two who later went to the White House: Jimmy Carter was the keynote speaker in 1972, and when Bill Clinton came in 1988 he also played his saxophone at an off-campus party.

Among this year's lineup, Gibson named U.S. Sen. Jim Webb of Virginia, Delaware Attorney General Beau Biden, state Rep. Patrick M. Rose of Texas and former U.S. Rep. Harold Ford Jr. of Tennessee as those with promising futures.

Also on the agenda: Geraldine Ferraro, who was the first woman on a U.S. presidential ticket, former presidential candidate Jesse Jackson and L. Douglas Wilder, Richmond mayor and the nation's first elected black governor.

"This is a huge year for America, and I wanted to celebrate the diversity of the Democratic Party," Gibson said.

The timing of this year's convention made it more difficult to attract speakers to the campus in the Shenandoah Valley, she said. The convention will make its prediction on the day of the South Carolina Democratic primary, when many prominent party leaders will be in that state.

About 90 percent of the 1,800 undergraduates work on the convention, Huang said, many of them for two to three years before the event. Law school students are also involved.

Gibson, a senior studying politics and poverty studies, said the convention was one of the reasons she went to W&L.

According to the convention's Web site, a campus visit by Williams Jennings Bryan in 1908 created such interest among Washington & Lee students that they decided to hold a model Democratic convention. That gathering correctly chose Bryan as the nominee.

The gathering has been the most accurate student convention in the nation, with 18 correct predictions in 23 meetings. Its record improved to 92 percent from 1948 through 2004, with the only miss the selection of Edward Kennedy rather than George McGovern in 1972.