“This isn’t a state or region-specific phenomenon, it’s nationwide,” said John Samples, director of think tank Cato Institute’s Center for Representative Government. “[But] registration doesn’t translate into voting, necessarily.”

Of the 148,389 voter registrations in Virginia since January, 45 percent come from adults aged 18 to 25. In Maryland, young voters comprise 46 percent of the state’s 131,428 registrants during the same time period. District registrants since January are 5,095 for ages 18 to 24 and 11,453 for older adults.

Experts attributed the spike primarily to enthusiasm surrounding Democrat Barack Obama’s presidential candidacy. Obama represents generational change, Samples said.

“It”s really an ongoing phenomenon that we won’t understand fully until it’s over,” said John Sides, assistant professor of political science at George Washington University. “[Obama] has clearly targeted and tried to mobilize young people.”

Young people vote less because they move often and are less motivated by  issues such as tax rates and education until they establish themselves and start families, experts said. They have trended Democratic in recent years, Sides said, as that party’s position on issues like gay rights and the environment have resonated.

Since the D.C. region leans heavily Democrat, it’s not surprising younger voters do too, said Daniel Head, D.C. Young Republicans communications director. And Obama’s campaign has effectively used new media like Facebook and podcasting, said Jim McBride, coordinator for the region’s Generation Obama.

“You don’t have to go to a campaign office,” McBride said. “You can download your own materials.”