What is wrong with EMILY’s List?

I read something just a few minutes ago that really pissed me off.  They decided to jump into another Democratic primary.  There is only one problem.  They are hurting Progressives by doing so.  Join me over the jump to find out more.

I just read this story a few minutes ago:

http://thehill.com/...

I believe you have to have a subscription to read it.  The gist of the story is that EMILY's List is backing a primary challenger to Steve Cohen in TN-09(Yes, Harold Ford, Jr.'s old seat).  It befuddles me as to why.  Why are they trying to primary one of the most progressive members of the House?  Is Nikki Tinker(who is the Ford Family Machine candidate) better than Cohen?  Has Cohen done his district wrong in anyway(unlike Al Wynn)?  It is one thing to primary odious people like Al Wynn, but Steve Cohen?  Can they give a good reason?  I hope EMILY's List will come to their senses, but according to the article they seem set in their ways.  I thought the idea was to defeat Republicans, not try to take down Progressives.  Given the challenges this fall is this a wise way for EMILY's List to spend money.  If anyone has more information on this, please note it in the comments.  I'm all for more women in the House and Senate.  Matt Stoller did a great post over at Open Left about the need for more women to run for office, as the more women that hold office, the more progressive the body usually is.  This example though is one time I have to cry foul.  It's hard enough getting the better part of "More and better Democrats".  There is no need to try and take one of the better Democrats out and replace him with a DLC'er.