"These impression-oriented potential voters are among the tens of thousands of people whose e-mail addresses the Obama campaign was bragging of having captured after the four Oprah events. They help make up the crowds who generate the "sense of momentum" coverage and the "movement" feeling. No one knows for sure whether it's real. No one will know for sure until the caucuses and primaries actually begin. It could end up that Obama is the one who goes poof in Iowa. Youth voters, especially, are regularly touted as a powerful weapon for whatever "movement" campaign has arisen in a given cycle, and they constantly disappoint."