A CNN/ORC International poll shows Republican Joni Ernst leading Iowa 's Senate race . The survey found that Ernst leads Democratic Sen. Chuck Grassley by a margin of 47 percent to 42 percent. That 's within the poll 's 4 percentage point margin of error .
A CNN/ORC International poll shows Republican Joni Ernst leading Iowa 's Senate race . Ernst is up 49 % to 47 % over Democrat Bruce Braley . That 's within the poll 's 4 percentage point margin of error .