Joe Bouchard and Allan Haggan Jr. drove from Fairfield to Bangor on Friday because they wanted to represent a type of diversity in the Maine Democratic Party.Their left-of-center politics have a characteristic Maine tinge: Among the top causes for the delegates to the two-day party convention were universal health care and gun rights, the latter of which they felt was a common attitude here but one not represented well in the national party. “We really want to make sure that there’s visibility on where we stand across the board, across the whole spectrum and not just kind of a stereotype at a singular national level,” Bouchard said. A wide-angled approach will be especially important this year for Democrats trying to maintain political power in Maine up against a midterm wall.