The two polls are affiliated with partisan organizations, and each shows their respective candidates ahead, but only by a 2-point gap. A Democratic poll released by Majority PAC and Center Forward gives Donnelly the lead, 45 percent to Mourdock's 43 percent, with 12 percent of voters undecided.

And a poll out from the Indiana Chamber of Commerce, which endorsed Sen. Dick Lugar (R-Ind.) in the primary but has supported Mourdock since he beat Lugar for the GOP nomination, gives Mourdock a 2-point lead over Donnelly, 41 percent to Donnelly's 39 percent, with 17 percent of voters still undecided.

The two are likely to remain locked in a tight battle, as the state looks to be going for Mitt Romney in the general election, though President Obama managed to take the traditionally-red state in 2008. 

The poll out from Majority PAC was conducted Aug. 9-12 among 601 likely voters and has a margin of error of plus or minus 4 percentage points, while the Indiana Chamber of Commerce poll was conducted Aug. 6-9 among 600 likely voters and has the same margin of error.