Of the nine candidates running for the 5th Congressional district, only two are women. Of those two, only one is a Democrat, so perhaps it's not surprising that EMILY's list, which in its own words works "to elect pro-choice Democratic women," would choose Elizabeth Esty to nominate. 
The full release is below:

EMILY’s List, the nation’s largest resource for women in politics, announced that it is fully recommending four women for the House of Representatives, including one incumbent:

·         Rep. Betty Sutton (OH-16)

·         Tarryl Clark (MN-08)

·         Elizabeth Esty (CT-05)

·         Dina Titus (NV-01)

Rep. Betty Sutton earns her endorsement this week after declaring her candidacy for the seat currently occupied by Republican Rep. Jim Renacci. Her current seat was divided during the redistricting process. EMILY’s List stands with Rep. Sutton to ensure she continues her strong leadership representing Ohioans in Congress. 

“On the List” was created because of the dramatic growth in the EMILY’s List community – now over 900,000 members – who are getting their information earlier, quicker and on the web. These supporters are ready to take action now and “On the List” makes sure candidates have early access to them. Today, Clark, Esty, and Titus move from “On the List” to a full recommendation.

“Women are leading the way back for Democrats in 2012,” said Stephanie Schriock, President of EMILY’s List. “We can take back the House, but only if we support our strong women candidates like Tarryl Clark, Elizabeth Esty, Dina Titus, and Betty Sutton. Their commitment to stopping the radical GOP agenda is firing up women voters across the country who are sick of the GOP ignoring the needs of middle class families.

“The four women we’re endorsing today are running fantastic campaigns and the entire EMILY’s List community is proud to have their back. With 2012 poised to be a great year for our candidates, this is the time to help these champions for women take back the House.”

In the 2009-2010 cycle, EMILY’s List raised more than $38.5 million to support its mission of recruiting and supporting women candidates, helping them build strong campaigns, and mobilizing women voters to turn out and vote. With a community of more than 900,000 members across the country, EMILY’s List is one of the largest political action committees in the nation. Since its founding in 1985, EMILY’s List has worked to elect 86 pro-choice Democratic women to the U.S. House, 16 to the U.S. Senate, nine governors, and hundreds of women to the state legislatures, state constitutional offices, and other key local offices. In the 2009-2010 cycle, EMILY’s List had the largest number of members and donors in our 25 year history.