Boston's T does go to the airport (and it is good public transit otherwise). Having taken this particular trip a few times though it is a bit of a pain and very confusing as you need to catch a connecting bus. So Menino isn't going to send Dem big wigs that way.
You are absolutely right about taking the connecting bus being confusing, especially for Dem bigwigs. I had lived in Boston area for 9 yrs and can testify that those having problems with butterfly ballots would not make it - EVER!