Iowa Democrats listen to former secretary of state Hillary Clinton speak during the 2015 Iowa Democratic Wing Ding in Clear Lake on Friday. (Melina Mara/The Washington Post)

Two independent groups allied with Democratic White House contender Hillary Rodham Clinton are teaming up on an ambitious effort to mobilize female voters in support of her, the latest example of how outside organizations financed by wealthy backers are seeking to shape the dynamics of the 2016 race.

Priorities USA Action, the lead super PAC backing Clinton, is working with Emily’s List to raise more than $20 million to reach women in battleground states through paid advertising and other voter outreach, The Washington Post has learned. The involvement of Emily’s List will be conducted through Madam President, a project of its independent expenditure arm.

The campaign will seek to drive up turnout among female voters — particularly young ones — with a message that the Republican presidential candidates would block access to health care for women and oppose fair pay. 2016 marks the first presidential contest in which the number of millennials eligible to vote will match the number of eligible voters from the baby boomer generation.

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“Women voters are the key to winning the 2016 elections, for Hillary Clinton and for Democrats up and down the ballot,” Stephanie Schriock, president of Emily’s List, said in a statement. “We are thrilled to be joining forces with Priorities to make sure every woman in this country understands that with a Republican in the White House, our rights, freedoms and opportunities will be on the chopping block.”

Democratic strategists said the recent remarks by the GOP field on women’s issues — such as the staunch anti-abortion stances by Sen. Marco Rubio of Florida and Wisconsin Gov. Scott Walker — provide an opening to highlight the differences between Clinton and her Republican opponents.

“The entire Republican field is a case study in extremism, and we must fight back against their agenda that would marginalize opportunities for women of every race, age, and economic background,” Guy Cecil, co-chair of Priorities USA, said in a statement.

One of the top surrogates for Clinton will be former Michigan governor Jennifer Granholm, who just left the board of Priorities to serve as a senior adviser at Correct the Record, a super PAC that is coordinating directly with the Clinton campaign on rapid response.

The collaboration between Priorities and Emily’s List spotlights how the super PAC is positioning itself as the hub in the constellation of independent groups backing Clinton. Earlier this summer, Priorities announced a fundraising agreement with American Bridge, a group focused on opposition research. The super PAC plans to roll out partnerships with other outside groups, as well, officials said.