Ignition will not turn all the way

The key will go into the ignition but will not turn all the way. The lights in the car and the radio will come on but it will not turn enough to turn the car on. The steering wheel moves freely from left to right and will not lock while this is happening, but will lock when the key has no problems. It feels like there is something inside the ignition that has fallen and will not allow the key to turn. I have used both mechanic key and the vehicle key and they have the same result. I am able to get it started but it takes a lot to get the key to turn. What could the problem be?