Obama, a U.S. senator from Illinois, led Sen. John McCain of Arizona 56 percent to 31 percent in a poll by The Hartford Courant and the Center for Survey Research and Analysis at the University of Connecticut, the newspaper reported.
"Obama is running away with the race," Samuel Best, director of the center, told the Courant. "Not only is he the overwhelming choice among Democrats, but he is attracting widespread support from key swing groups."
Among those groups were Catholics, who preferred the Democrat by 9 percentage points, and those over 65, where Obama held a 6-point edge, the newspaper said.
If Obama posts a victory in Connecticut, it would give Democrats their fifth consecutive presidential victory in the state, which started with Bill Clinton's 1992 performance.
The survey included 502 likely voters polled between Oct. 18-22 and had an error margin of 4 percentage points.