This has become a backbone of Democratic strategy. Throw out any outlandish, unfounded acquastion possible. Then hope there is insufficient time for the Republicans to respond. It would appear that at this one instance, they came out with their lies too early and fortunately gave time for a solid reponse.
Vote Republican and Save America
They thought they could paint Coburn as a wild eyed crazy lunatic. The problem is this has become standard procedure for Democrats. Before, it used to only be in the final moments of the campaign when they would really swing the hammer. It's just revealing what they really are like.
Say hello to Senator Coburn in November!