She was chagrined at The Nation 's recent publication of a column by conservative education activist Ron Unz arguing that liberal education reform has been an unmitigated failure.
She did not like the column by Ron Unz. 
mnli hypothesis: She did not like the column by Ron Unz.  premise: She was chagrined at The Nation 's recent publication of a column by conservative education activist Ron Unz arguing that liberal education reform has been an unmitigated failure.