The Quinnipiac University poll released Wednesday found Democrats are favored in 2014 congressional races over Republicans, 41 percent to 37 percent.
In addition, 48 percent of voters indicated they would like one party to control both houses of Congress and the White House.
"The Democratic edge in the so-called congressional ballot is small at this point in the cycle, but there has been a consistent Democratic edge for several months," said Peter A. Brown, assistant director of the Quinnipiac Polling Institute. "The question, of course, is whether that margin will be there in 18 months when voters go to the polls."
Historically, a two-term president's party loses seats in Congress in the sixth year of his presidency.
The poll of 1,471 registered voters was conducted by phone April 25-29. The margin of error is 2.6 percentage points.