Iowa Senator Tom Harkin has left Los Angeles today, headed for China.Harkin’s making the trip because he’s undecided about an upcoming vote on granting permanent normal trading status to China.Harkin says he’ll get a better feel for what’s really happening by going there rather than relying on State Department briefings and staff reports.Harkin will try to lead U-S Customs Agents into Chinese prisons. A U-S/Chinese agreement calls for Customs Agents to have access to the prisons to ensure prison labor isn’t used to make goods shipped to the U-S. Harkin says the nagging question in his mind is whether China will change more rapidly by open trade or by tough sanctions, and Harkin says the trip may help him figure that out.