Democratic candidate, who has a history of opposing gun regulation, to speak near site of mass shooting that injured congresswoman Gabrielle GiffordsIf there is a time and place for Bernie Sanders to start squirming over gun control, you might expect it to be at his rally in Tucson on Friday night.He will address a crowd at Reid Park, just 11 miles from the supermarket parking lot where a deranged gunman murdered six people and wounded 13, including congresswoman Gabrielle Giffords, in 2011.