I got a card in the mail last week that I can't stop thinking about. I'd lost a close friend, and Patti Russo wanted me to know that she was thinking about me and hoped I was doing OK. I also got a text from Anne Moses telling me she was there if I needed to talk.

Why is this unusual? Because Patti, Anne and I run national political organizations training women to run (Women's Campaign School at Yale, Ignite and Running Start). We are direct competitors, fighting for the same funding, the same publicity and a share of the same demographic. But the women's political world that we belong to is groundbreaking in our commitment to work together to get more women elected, rather than to pull each other down to elevate our own groups.

When I speak to women around the world about barriers to leadership, I consistently hear that other women are their worst enemies. This is so widespread that I'd put it in the top 10 of reasons why women feel they can't succeed. Women are said to be the worst bosses, not supportive of their peers' ambition and reluctant to pull up those coming behind them. The "mean girls" stereotype is alive and well. Meanwhile, the men have the Old Boys Club which still seals deals on the golf course or over a cigar at the club. They sponsor each other while we too often hold each other back. How can women hope to succeed in business and politics when we aren't opening doors for each other?

A few years ago, philanthropist Swanee Hunt created a group called Political Parity to address how we can do a better job of getting more women elected to political office. She invited the leaders of women's political empowerment groups from around the country to meet regularly to share ideas and find ways to work together. And while I had a passing acquaintance with these women before our Parity meetings, it was at these day long sessions that I developed real relationships with many of them that were both personally fulfilling and that led to innovative partnerships. These meetings remind us that our greatest strength comes from putting our heads together to solve problems, and that as allies we are far more powerful than we would be in our individual silos, carefully guarding our ideas.

At an impromptu lunch this July during the Democratic National Convention, Russo, Erin Loos Cutraro (She Should Run), , Erin Vilardi (Vote Run Lead), Cynthia Terrell (Representation 2020), Tiffany Dufu (Levo League), Jessica Grounds (Project Mine the Gap) and I sat together talking. It can be lonely being the head of an organization, difficult to be a working mother, hard to navigate fundraising, board relationships and keeping staff happy. We talked equally about personal trials and business opportunities. We laughed a lot. I am so grateful to this network of women who support me and make me smarter about how I do my job.

And I'm glad that we are setting a good example for the women we serve that we are stronger when we work together.

news.com/opinion/articles/2016-08-29/cultivate-the-old-girls-club-to-encourage-women-to-support-each-other