Last week, I had a whirlwind visit to Chicago to talk about my new book. Fortunately before my flight to Charleston, West Virginia, I had time in the morning to visit Karen Lewis at an assisted living facility where the care is excellent.

Karen is a brilliant charismatic woman who taught science in the Chicago public schools for more than 20 years. In 2010, Karen led a faction of the Chicago Teachers Union called the Caucus of Rank and File Educators, which swept to victory in the union elections. She became president of the CTU. She was a strategic organizer who worked to build alliances with parent and community groups. In 2012, the CTU voted to strike. The legislature, egged on by Gates-funded Stand for Children, passed a law that they thought would make a strike impossible by requiring a vote of 75% of the membership. Karen and her team won the approval of about 90% of the members and led a successful strike that had the support of parents and communities because they understood that teachers were striking for their children.

Karen was an articulate and greatly admired visionary. She planned to run for mayor against Rahm Emanuel in 2015, and her own polling suggested that she would beat him handily.

Tragically, Karen was diagnosed with a brain tumor in October 2014. Since then, she has had a series of setbacks, including a stroke. Life is so unfair. Karen is only 66.

When I saw her, she was happy that I visited. As I expected, she is disabled and has limited mobility. But despite the terrible blows that life has dealt her, she is spirited, still has a sense of humor, and is interested in what’s happening in the world. I told her that wherever I go, people remember her as the Mother of the Resistance. They remember that she stood up to a bully and won. I showed her the photo of her in my book and told her that her legacy is there whenever teachers stand together and demand better conditions for teaching and learning. I told her she was the spark that lit the fire by her example and the powerful union she created. I told her she will never be forgotten.

She was a strong labor leader, a saucy woman who was fearless, wise, and funny.

I was glad I saw her but sad to see the tragedy she endured when she was at the peak of her promise. Her beloved husband John sees her every day and has been by her side through the best of times and the worst of times.

I wrote a note in the book I gave her. Simply, “Karen, I love you. Diane.”