On the surface, Michael Johnston might have seemed an unlikely choice to fill the seat of Peter Groff, the departing president of the state Senate. After all, Groff is an African-American, as are Rosemary Marshall, Anthony Graves and Renee Blanchard, the three candidates aside from the Caucasian Johnston for the position. And yet Johnston's profile has risen into the rarefield political air thanks to the endorsement of Barack Obama, who praised Johnston's innovative work as principal of Mapleton Expeditionary School of the Arts, or MESA. Last year, Jessica Centers authored a comprehensive profile of Johnston, headlined "Barack Obama Gives Principal Michael Johnston Extra Credit." It's an excellent way to get to know your latest state Senator.