For months, Elizabeth Warren and Bernie Sanders were amiable rivals, vying for left-leaning voters and the Democratic presidential nomination without directly attacking each other. So much for that! After Peter Kadzis and Adam Reilly size up the end of the Sanders-Warren detente, Peter chats with Kristin Johnson, a/k/a @krissycabbage, about why she and other Boston education activists are skeptical of Boston Mayor Marty Walsh’s big new push for public-school equity.