BOSTON — Opponents of Republican efforts to overhaul the country's health care system are planning to rally in front of the Massachusetts Statehouse.The group of health professionals, patients, and legislators are part of a nationwide push to highlight what they say is the ongoing threat of attacks on the country's safety net programs.Protesters say the National Day of Action for Improved Medicare for All is part of a push to ensure all Americans have health care.The rally is planned for Saturday at noon in front of the Massachusetts Statehouse.