PRINCETON, NJ -- President Obama continues to enjoy a substantial lead over Mitt Romney among voters under 30, but these youthful Americans are significantly less likely than average to be registered to vote, and significantly less likely than those who are older to say they will definitely vote in next November's election.

President Obama this week made an explicit effort to shore up his support among young voters, embarking on a "college tour" of campuses in North Carolina, Colorado, and Iowa. Obama called on Congress to pass legislation that would keep the interest rates on student loans from doubling this summer, as they are scheduled to do under current law. Romney, in a rare instance of agreement with Obama, also came out in support of Congress' taking this action, marking his own effort to gain support among the youth vote.

It's clear at this point that Obama maintains the decisive edge when young voters are asked whom they support for president, as he did in 2008. Voters aged 18 to 29 in Gallup's most recent five-day average, April 20-24, support Obama over Romney by 35 percentage points, 64% to 29%, and -- compared with older age groups -- have been disproportionately supportive of Obama since Gallup's tracking began on April 11, albeit by differing margins. Obama's lead is five and four percentage points, respectively, among those 30 to 49 and 50 to 64, while Romney leads by 12 points among those 65 and older. Overall, for the April 20-24 five-day period, Obama leads by six points, 49% to 43%.

The practical value of Obama's broad support among young voters is lessened by the fact that only six in 10 of these voters say they are registered to vote, and that fewer than six in 10 who are registered say they will definitely vote in November's election. By way of contrast, Romney's relatively strong support among voters 65 and older is more politically potent; these older voters are well above average in their voter registration percentage, and are most likely of any age group to say they will definitely vote in November's election.

Bottom Line

It is a well-established fact of American political life that young voters are not dependable voters. In a close election, however, the support of even low-turnout groups can be decisive. Thus, Obama's campaign team apparently decided that his visits to college campuses this week could pay off if he is able to motivate and inspire young voters who already support him to get out and vote in November. Romney's agreement on the issue of freezing student-loan interest rates was no doubt an attempt to avoid leaving the youth vote totally to Obama. It is clear at this point, however, that Romney has greater potential payoff with more politically active older voters, among whom his support is much stronger.

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