John McCain leads Barack Obama by four points.
In a recent poll by the conservative Civitas Institute, the Republican presidential nominee had 45 percent, followed by Obama at 41 percent and Libertarian nominee Bob Barr at 2 percent. Twelve percent were undecided.
In the previous survey for the group, McCain led Obama 44-39. Barr was not included in that poll. Other surveys have shown Barr gaining as much as six percent.
"Both Senator McCain and Senator Obama improved their numbers over last month by solidifying the support of their party’s base voters," said executive director Francis DeLuca in a statement. "Obama increased his support among Democrats by five percent, while McCain increased his support among Republicans by three percent."
The live survey of 600 likely general electoin voters was taken June 11-13 by TelOpinion Research of Alexandria, Va. The margin of error is plus or minus 4 percentage points.

