Time Magazine is weighing in today with its own poll on the presidential race. The poll of registered voters shows Barack Obama leading John McCain, 43-38 percent, what the authors are saying is "only a slight bounce from Hillary Clinton's departure from the campaign early this month. "

That's a narrower lead than Time's February poll, where Obama led McCain 48-41 percent. Twenty-eight percent thought they could change their mind before election day.

The poll was conducted June 19-25 and has a margin of error of +/- 3.5 percentage points.

Check out our video on why polls differ.