EMILY's List on Tuesday endorsed Rep. Colleen Hanabusa (D-Hawaii) in her bid to unseat Sen. Brian Schatz (D-Hawaii), giving her a potentially big boost in the race.

The endorsement sets up a fight between the deep-pocketed group, which backs pro-abortion-rights Democratic women, and the Democratic Senatorial Campaign Committee (DSCC), which is backing Schatz.

"Colleen Hanabusa is an experienced progressive champion who has spent her career serving the people of Hawaii with passion and integrity," EMILY's List President Stephanie Schriock said in a statement Tuesday.

"She's a glass ceiling breaker who was the first woman in Hawaii, and first Asian American woman in the country, to lead a state legislative chamber. Hawaii has a rich tradition of women's leadership and EMILY's List is proud to have helped Colleen be a part of it. Now the EMILY's List community is ready to fight for her every step of the way so that she can take her place as a senator from Hawaii," she added.

EMILY's List often spends heavily on behalf of its candidates and could provide Hanabusa with key support, given Schatz's early fundraising edge. Schatz raised $1.1 million in his first fundraising quarter in office, while Hanabusa brought in $230,000.

It's unlikely the DSCC will spend much to help Schatz — the seat will likely remain in Democratic hands regardless of who wins the primary — but he will likely benefit from the organization's infrastructure and donor list. Senate Majority Leader Harry ReidHarry Mason ReidWATCH: There is no Trump-Russia collusion and the media should stop pushing this The demise of debate in Congress ‘North by Northwest,’ the Carter Page remake MORE (D-Nev.) and DSCC Chairman Michael BennetMichael Farrand BennetColorado senators pitch immigration compromise Colorado senators mark Olympics with Senate hallway curling GOP Senate candidate fundraising lags behind Dems in key races MORE (D-Colo.) have already donated to Schatz's campaign.

The conflict between EMILY's List and the DSCC might end up much less heated than in some earlier campaigns where they were on opposite sides. The DSCC’s decision to back now-Sen. Chris MurphyChristopher (Chris) Scott MurphyLawmakers feel pressure on guns Trump to take steps to ban bump stocks Kasich’s campaign website tones down gun language after Florida shooting MORE (D-Conn.) over then-Connecticut Secretary of State Susan Bysiewicz (D) in 2012 led to some serious sparring, for instance.

Hanabusa publicly announced she'd challenge Schatz last week. She'd spent months mulling whether to run against him or Hawaii Gov. Neil Abercrombie (D), who appointed Schatz to the seat despite a deathbed request by the late Sen. Daniel Inouye (D-Hawaii) that she replace him in the Senate. Inouye's widow endorsed Hanabusa shortly after she made her campaign official.
Sources close to Hanabusa told The Hill that the congresswoman was furious about Abercrombie’s decision.

In addition to the DSCC's backing, Schatz has the support of the League of Conservation Voters, a major environmental group. He also has ties to President Obama, who remains immensely popular in the state.

Schatz was one of the first in the country to endorse Obama for president in 2006, was part of a draft effort to get him to run and was active in Obama’s Hawaii campaigns. He chaired the state party and acted as an Obama spokesman.

—Updated at 4 p.m.