In Iowa, Rep. Bruce Braley (D) leads business Mark Jacobs (R) 43-42 and state Sen. Joni Ernst (R) 44-40.
In Michigan, Rep. Gary Peters (D) leads former secretary of state Terri Lynn Land (R) 42-37.
In New Hampshire, Sen. Jeanne Shaheen (D-N.H.) leads former Massachusetts senator Scott Brown (R) 49-43.
Iowa and Michigan, in particular, have emerged as top GOP targets as the national environment has become slightly more favorable to the GOP.
In the fifth poll conducted, Senate Minority Leader Mitch McConnell (R-Ky.) narrowly leads Kentucky Secretary of State Alison Lundergan Grimes 46-45. Basically every poll has shown the Kentucky Senate race to be a virtual tie.
Previous surveys from the same pollster for the same group, BuildKXLNow.org, showed tight races in North Carolina and Arkansas, with the GOP slightly ahead in Louisiana.