Washington ? Even though young voters make up the largest voting bloc in the country, experts say they are less likely to vote Tuesday than any other major voting bloc in America.

Meager turnout by young people is nothing new, but today’s 43 million 18- to 24- year-olds constitute almost 25 percent of the electorate and could be a major political force, according to the Youth Vote Coalition, a Washington-based group that promotes political participation by young people. Yet if young people vote at rates no higher than they have in the past, only 13 percent will vote Tuesday, Youth Vote projects.

The issues of the day might seem tailor-made to propel young people to the polls: a slumping economy, which has reduced financial aid to college students and cut jobs for young people; a possible war with Iraq; and post-Sept. 11 developments that made questions of politics and government sharply relevant.

But no evidence has emerged to suggest that more young people are likely to vote this year. The top issues among 18- to 24-year-olds are terrorism, the economy and crime, according to a nationwide survey sponsored by the Youth Vote Coalition and conducted by Lake, Snell and Perry, a polling firm for Democrats. These issues differ little from those that matter to the rest of the electorate.

The survey found that young adults do not vote because: They don’t care; they think voting makes no difference; they’re uninformed; or they’re too busy.

It may take a new Great Depression or a controversial war or extraordinary leadership to turn young people to more active political involvement, said Curtis Gans, director of the Committee for the Study of the American Electorate, a vote-research group.

“There is nothing in the climate of this campaign that appeals to the idealism of young people,” Gans said.

“Candidates don’t court the young vote because they are told by political consultants to not talk to young people,” said Richard Thau, president of Third Millennium, a research center representing “Generation X,” or Americans born between 1964 and 1977.

Elections in nonpresidential election years suffer from low voter turnout for every age group, noted Democratic Party pollster Mark Mellman, of the Washington-based Mellman Group. But young people turn out less even than others.

Only about 16 percent of 18-to 24-year olds voted in 1998, the last midterm elections, compared with almost 42 percent for the entire electorate, according to Census Bureau data.

John McHenry, a Republican pollster, said campaign strategists didn’t tell candidates to ignore young people, but “you certainly want to have your candidates focusing on the groups that will turn out and vote.”