Massachusetts voters will get a chance Tuesday to step up to the plate and vote in the 2012 presidential primaries. The polls will be open from 7 a.m. until 8 p.m. For more information on where to vote, residents can contact their local town clerk, the secretary of state’s office said. Only residents who registered to vote by Feb. 15 will be allowed to cast ballots. If enrolled in a political party -- whether Democratic, Republican, or Green-Rainbow-- people can only vote for candidates in those respective primaries. Independent, or “unenrolled,’” voters have the option of voting in any of the primaries without having to commit to a party.