By Seth Daniel

For the South End’s Dr. Jon Santiago, the path from Peace Corps activist to Army Reserve captain to Emergency Room doctor, and now, to candidate for state representative makes perfect sense.

All four are about doing whatever he can to help others, he said.

This week, Santiago – the former vice chair of the Ward 4 Democratic Committee, a community activist and an emergency room doctor at Boston Medical Center (BMC) – announced that he will take that fourth step in his unique path by running for state representative in the 9th Suffolk District – a seat now held by long-time State Rep. Byron Rushing.