Ned Lamont, left, defeated incumbent Sen. Joe Lieberman in the Democratic primary.
(CNN) -- A new poll by the American Research Group indicated a statistical dead heat in the U.S. Senate race in Connecticut between upstart Democratic nominee Ned Lamont and incumbent Sen. Joseph Lieberman.
Some 44 percent of respondents deemed "likely voters" supported Lieberman, while 42 percent said they would vote for Lamont in the November election. This gap was well within the margin of error of plus-or-minus 3.5 percentage points. Republican nominee Alan Schlesinger got backing from 3 percent of likely voters. (Full results
Late last week, Quinnipiac University released its own poll showing Lieberman with a healthy, double-digit lead over Lamont -- 53 percent of likely voters to 41 percent. (Full story
The main difference between the two polls lay in the percentage of respondents who said that they were undecided: 2 percent in the Quinnipiac survey compared to 11 percent in the ARG poll, more than 5 times larger.
According to the ARG poll, some 65 percent of Democrats said they'd vote for Lamont, compared to 30 percent for Lieberman. Overwhelming support from Republicans -- who backed him 57 percent to Lamont's 18 percent -- propelled Lieberman.
Lieberman led Lamont 68 percent to 32 percent among the 9 percent of likely voters who said they had a favorable view of both top candidates. Lieberman was viewed favorably by 56% of likely voters, while 47 percent had a favorable opinion of Lamont.
In a hotly contested, high-profile Democratic primary, Greenwich cable executive Lamont rallied from political obscurity to upend Lieberman -- the party's 2000 vice presidential nominee -- 52 percent to 48 percent. Throughout the campaign, Lamont criticized the three-term senator's support for the Iraq war. After conceding the primary, Lieberman said that he would continue in the race as an "independent Democrat." (Full story