Iowa Senator Charles Grassley is calling on the independent groups that have been running commercials critical of the new prescription drug benefit for seniors to pull those ads. Grassley also wants the groups to stop “bad-mouthing” the plan as he says some low-income seniors aren’t signing up for free prescription drugs.Grassley says the groups are making false accusations for political purposes. Grassley at one point pounded the lectern as he talked about the ads yesterday at a news conference in New York City. “It’s fair to say I’m a little incensed,” he said. Grassley says up to three MILLION poor senior citizens haven’t signed up for the six-hundred dollars worth of prescription drug coverage they are now due under the new law. Grassley conceeds the ads are not currently running on Iowa t-v stations, but he says he they have before and he expects them to air again sometime before the November election.