Retiring Rep. David Obey (D) on Monday announced that he is backing Wisconsin state Sen. Julie Lassa to fill the seat he has held for 21 terms.

The announcement came in the form of a fundraising appeal for Lassa two days before the end of the second quarter.

“I have known Julie Lassa for more than a dozen years, and in that time I have seen her work in both the public and private sector,” Obey wrote. “She has focused like a laser on creating jobs, holding government more accountable and protecting our children and families from hazardous chemicals in the products we use every day.”

Obey’s endorsement of Lassa isn’t a surprise. State Democratic officials quickly rallied around Lassa after Obey’s retirement announcement in May. Other establishment Democrats who had considered the contest stepped out of the race to clear the field for her and, in late May, Lassa earned a key endorsement from EMILY’s List.

One of the reasons Democrats were quick to unite behind Lassa is because Republicans are determined to make a serious attempt to win the open 7th district seat this fall. The likely GOP nominee is Sean Duffy, a county prosecutor who began campaigning last summer and had raised over half a million dollars by the end of the first fundraising quarter.