Where is Obama's Youth Vote Going?

Michael Barone has some interesting poll numbers

The first bit of evidence comes from the July 10-13 ABC/Washington Post poll. It asked registered voters if they were "certain" to vote. Only 46 percent of voters under 30 said they were -- substantially lower than the 66 percent who said so in the ABC/Washington Post poll taken Feb. 28-March 2, at a time when Obama was enjoying a string of primary and caucus victories and before the sermons of the Rev. Jeremiah Wright were circulated on youtube.com on March 13. The 46 percent of young voters saying in July they were certain to vote was far lower than the 79 percent of 65 and over voters who said they were.