NASHVILLE, Tenn. — As the rest of the nation debates the feasibility and humanity of lethal injections against a backdrop of scarce drugs and botched executions, Tennessee has come up with an alternative: the electric chair. Republican Gov. Bill Haslam signed a bill into law late last week allowing the state to electrocute death row inmates in the event prisons are unable to obtain the drugs. The drugs have become more and more scarce following a European-led boycott of drug sales for executions. Tennessee …