[cnn-photo-caption image= http://i.cdn.turner.com/cnn/2008/images/06/03/art.obamamccain.gi.jpg caption="Obama has a slight lead over McCain in a new poll."]
(CNN) - On the same day Barack Obama could clinch the Democratic nomination for president, a new poll out Tuesday shows the Illinois senator holds a slight lead over presumptive Republican nominee John McCain among likely voters nationwide.
The new USA Today/Gallup survey shows the Illinois senator with a 5 point advantage over McCain among likely voters, 49 percent to 44 percent. That margin is just outside the poll's 4 point margin of error, meaning Obama appears to hold a slight advantage over the Arizona senator with five months remaining until voters weigh in at the polls.
The survey shows Hillary Clinton also leads McCain, though with a margin that is just with the poll's sampling error. According to the survey, the New York senator bests McCain by 4 points, 48 percent to 44 percent.
A similar poll conducted by USA Today/Gallup last month showed John McCain beating both candidates - a potential sign the ongoing Democratic presidential race has not hurt the party's chances in November.
In a recent CNN analysis of several national polls, Obama holds a 1 point lead over McCain, 46 percent to 45 percent. Meanwhile, Hillary Clinton holds a 4 point lead over McCain, 48 percent to 44 percent.