There are big problems in education. The achievement gap. High dropout rates. Struggling urban schools.

But this week, some presidential candidates are sniping about something that will do little to address any of those issues: whether the issue of same-sex marriage belongs in an elementary school classroom.

Republican Mitt Romney, a former governor of Massachusetts (where same-sex marriage is legal), lashed out at the Democratic candidates for their answers to a question during a debate on Wednesday night in New Hampshire sponsored on MSNBC. They were asked if they would approve of a teacher reading a story to 2nd graders that involved same-sex marriage. (Read the transcript here.)

The Democratic candidates who got a chance to answer that hot-button question were the front-runners--Sen. Barack Obama of Illinois, Sen. Hillary Rodham Clinton of New York, and former North Carolina Sen. John Edwards.

Edwards said he was “absolutely” comfortable with such material being discussed: “What I want is I want my children to understand everything about the difficulties that gay and lesbian couples are faced with every day, the discrimination that they’re faced with every single day of their lives,” according to the transcript.

Obama echoed many of those thoughts. “You know, the fact is, my 9-year-old and my 6-year-old’s -- I think, are already aware that there are same-sex couples.”

Clinton was probably the most evasive. “With respect to your individual children, that is such a matter of parental discretion.”

Thursday, Romney criticized the candidates in a statement for being “out of touch.” He continued: “This is a subject that should be left to parents, not public school teachers.”

What do you think? Should 2nd graders be exposed to this subject? Should the presidential candidates even be talking about it?