While partisan polls tend to skew towards their candidate and should be viewed skeptically, this is close to the results of a recent poll from the conservative pollster Rasmussen, which had Mourdock narrowly leading by 42 to 40 percent. The two polls indicate that the race is indeed a "toss-up" despite the state's lean toward the GOP.

The poll of 601 likely voters was conducted by Global Strategy Group between Aug. 2-5 and has a margin of error of 4 percent. Its partisan composition, giving the GOP a eight-point advantage, is close to the average performance in the state.