The first full round of tracking poll interviews after Barack Obama clinched the Democratic Presidential Nomination found that 36% of voters nationwide say they are certain to vote for Obama in November and 34% are certain they will vote for McCain. That leaves a very significant 30% who are not certain to support either of the presumptive nominees.

That 30% who could change their mind includes 12% who currently lean towards or support Obama and 11% who currently lean towards or support McCain. Two percent (2%) say they will vote for a third party candidate and 5% are undecided. Obviously, with the levels of base support so close, the candidate who can reach the majority of these early swing voters will emerge victorious on Election Day.

These voters have a generally positive view of both Obama and McCain. Fifty-six percent (56%) give favorable reviews to the Democratic candidate and 53% say the same about the GOP hopeful. Thirty-six percent (36%) have a favorable opinion of both and 22% have an unfavorable opinion of both.

The following demographic profile of these potentially decisive voters is derived from Rasmussen Reports telephone survey interviews with 921 voters who are uncommitted or could change their mind between now and Election Day. The interviews were conducted on June 3-6, 2008. Those are the three nights following the night that Obama wrapped up the nomination.

Partisan Identification: 35% Democratic, 24% Republican, 41% Unaffiliated.

Among those who are totally undecided and don’t even lean towards one candidate or the other at this time--41% are unaffiliated with either major party, 35% are Democrats, and 19% are Republicans.

Among all Republican voters, 70% are certain to vote for McCain, 10% say they’re for McCain but could change their mind, and 4% lean towards McCain.

Among all Democratic voters, 66% are certain to vote for Obama, 12% say they’re for Obama but could change their mind, and 2% lean towards Obama.

Among all unaffiliated voters, 29% are certain to vote for McCain and 12% support the GOP candidate but could change their mind. Twenty-four percent (24%) are certain to vote for Obama while 12% say they support him but could change their mind.

Ideology: 13% Very Conservative, 21% Somewhat Conservative, 40% Moderate, 18% Somewhat Liberal, 4% Very Liberal.

From a slightly different perspective, 33% are Social Conservatives, 37% are Moderate on Social Issues, and 26% are Social Liberals.

34% are Fiscal Conservatives, 52% are Fiscal Moderates, and 7% are Liberal on Fiscal Issues.

Gender: 56% Women, 44% Men.

Income: 55% under $60,000 annual income. 26% above $75,000.

Race: 82% White, 4% Black, 14% Other (mostly Hispanic).

Among all White Voters nationwide, McCain currently leads 52% to 41%. Among African-American voters, Obama leads 95% to 5%. Among all other voters, Obama leads 54% to 36%.

Age: 13% are Under 30: 36% are 30-49; 32% are 50-64; and 19% are 65+.

Education: 26% High School Graduate or Less Education, 53% Attended or Graduated College, 21% Attended or Completed Graduate School.

All data was compiled from surveys conducted for the Rasmussen Reports daily Presidential Tracking Poll.