Another poll shows Iowa’s U.S. Senate race is a dead heat.

Democrat Bruce Braley and Republican Joni Ernst each had the support of 43 percent of registered voters who were surveyed by the Marist College Institute of Public Opinion for NBC News. The two candidates still have work to do in introducing themselves to more Iowans. One-third of those surveyed said they are either unsure about the candidates or have never heard of them. Another 14 percent were undecided.

The poll found almost six out of 10 the Iowans surveyed gave Republican Governor Terry Branstad a positive job approval rating. Branstad led Democratic challenger Jack Hatch by 15 points in the poll.

Pollsters also pegged President Obama’s job approval rating in Iowa at 37 percent.

The poll’s margin of error is 2.5 percent. It was conducted from Monday, July 7th through the 13th, which was Sunday.