MADISON, Wis. (AP) — A new poll of Wisconsin voters finds similar approval ratings for Democratic President Barack Obama and Republican Gov. Scott Walker. The Wisconsin Public Radio/St. Norbert Survey was released Wednesday. It says 48 percent of voters approve of Obama while 50 percent approve of Walker. The numbers represent slight declines for each. The poll gives Congress overall a 15 percent approval rating. Democratic House members have a 36 percent approval rating, compared to 32 percent for House Republicans. Republican Sen. Ron Johnson is still somewhat unknown in his home state. The poll says 33 percent of voters either haven't heard of him or have no opinion. The telephone survey of 400 people was conducted between Oct. 9 and Oct 21. The margin of error is plus or minus 5 percentage points.