In the end, it’s all about turnout.

President Barack Obama has been trying to rev up young voters, who played a strong role in his own election, to encourage them show up at the polls on Election Day through appearances on MTV, next week’s “The Daily Show with Jon Stewart,” and an interview with “Rolling Stone” magazine. USA-POLITICS/

But a Harvard University poll of voters under age 30 finds midterm enthusiasm waning as the Nov. 2 election approaches.

“In most election cycles, it is expected that interest in voting will increase as the election draws near — in the 2010 midterm elections, interest in voting among Millennials (18-29 year olds) has been decreasing over the course of our last three surveys,” the report says.

A bar graph shows that in the October survey 27 percent of young Americans said they would definitely vote in the midterms, down from 36 percent last November.

There’s been a lot of chatter about the enthusiasm gap that shows more Republicans than Democrats saying they are likely to vote in this election. But what about the generation gap?