PORTLAND, Maine — With stark political divides on abortion, gun violence and other issues threatening to overshadow their meeting, the nation’s governors sought to find common ground — on other issues.The National Governors Association formally kicked off its summer gathering Thursday, the first in-person meeting since 2019, before the COVID-19 pandemic. It follows recent U.S. Supreme Court rulings that have deepened the rift between red and blue states, by overturning Roe v. Wade and striking down gun …