PORTLAND, Maine — Maine’s independent senator has joined a group of colleagues in support of President Joe Biden’s plan to use the Defense Production Act to increase the production of medical supplies during the coronavirus pandemic.Sen. Angus King, who caucuses with Democrats, and 25 other senators said in a statement Thursday that the Biden administration should use executive action to “utilize all appropriate authorities under the DPA and deploy a more functional response to the COVID-19 pandemic.” The senators said utilizing the Defense Production Act would help the country reach its goal of vaccinating enough people to reach the herd immunity threshold. King and the senators said the use of the act is necessary to produce enough medical, testing and protective equipment supplies to successfully defeat the virus. Biden on Thursday signaled his intent to use the act.