Young and returning voters continue to flock to Sen. Barack Obama, but the potentially game-changing question of how heavily they will turn out for Tuesday's election still lingers.

A new poll shows that 69% of new and returning voters plan to vote for Sen. Obama, up from 61% just a month ago. In the survey, conducted by The Wall Street Journal, NBC News and the MySpace networking Web site, just 27% said they planned to vote for Sen. John McCain. (See full results.)

The...