Yes, everyone know that younger voters are part of Barack Obama's electoral "base," but it's sometimes hard to grasp the sheer magnitude of Obama's popularity among "millenials." A new survey by USA Today/MTV and Gallup helps.

Here's the bottom line, from Susan Page:

A USA TODAY/MTV/Gallup Poll of registered voters 18 to 29 years old shows Democrat Barack Obama leading Republican John McCain by 61%-32%, the most lopsided contest within an age group in any presidential election in modern times.

"Modern times" means since 1976, when publicly released exit polling began. John Kerry won under-30 voters by an 11 point margin. In case you're bad at arithmetic, Obama's margin in this new survey is 29%.

Clearly, John McCain's problems with young voters weren't helped by his selection of 44-year-old Sarah Palin--the youngest candidate on either ticket--as his running-mate. In the new survey, Palin's favorable-unfavorable rating is 25/46 (McCain's is 43/45; Obama's is 71/23; and Biden's is 43/35), and 55% of these under-30 voters think Palin's not qualified to become president.

The size of the under-30 vote will, of course, determine its value to Obama. In the Democratic primaries, the percentage of the overall vote cast by under-30 voters nearly doubled from 2000, the last year with competitive primaries. The new voter registration numbers are certainly impressive: In Virginia, for example, which Bush won by 260,000 votes in 2004, there are more than 300,000 new voters on the rolls, and 41% of them are under 25.