Progressive candidates have scored at least 10 primary victories while trying to storm the Rhode Island General Assembly, representing a shot across the bow of the establishment Democrats who have typified the legislative mainstream on Smith Hill.

The results became clear after the state Board of Elections on Thursday added the results of tens of thousands of mail ballots to voting done at polling places on Tuesday.

State Senate President Dominick Ruggerio, who spent close to $100,000 on his campaign, held off a tough challenge by Lenny Cioe, a nurse who was one of the candidates backed by the progressive Rhode Island Political Cooperative.

But candidates backed by other liberal groups, including the Working Families Party and Reclaim Rhode Island, scored a string of primary victories.

While some of the winners face general election rivals, the progressive presence in the General Assembly is likely to be larger in the next session.

That is expected to spark sharper debate about tax policy and some other key issues as Rhode Island faces a current deficit of more than $800 million due to the pandemic.

Some of the progressives have indicated they are unlikely to support Ruggerio or House Speaker Nicholas Mattiello (who faces a general election race with Republican Barbara Ann Fenton-Fung) during a traditional January vote on leadership.

One of the most notable primary wins was first-time candidate Cynthia Mendes’ defeat of Senate Finance Chairman Billy Conley of East Providence. Final results show that Mendes got 61.5 percent of the vote, in a district that also includes part of Pawtucket.

The other progressives winning Senate primaries were Tiara Mack, who defeated longtime Providence Sen. Harold Metts; Jonathon Acosta, who ousted Sen. Elizabeth Crowley of Central Falls; former Sen. Jeanine Calkin, who won her rematch with Sen. Mark McKenney, and Kendra Anderson, who won a hard-fought four-way primary in Warwick with 30.9 percent of the vote.

In a statement, the Co-Op said, “RI Political Cooperative candidates – who all pledged to refuse contributions from the fossil fuel industry and corporate PACs – were outspent by their opponents across the board. Organizers said it was the quality of its candidates, the strength of its grassroots organization and the appeal of its policy agenda that made it possible to overcome the formidable financial advantage enjoyed by its opponents.”

In the House, the progressive winners included David Morales, a member of the Democratic Socialists of America, who won a three-way primary, defeating Rep. Daniel McKiernan of Providence with 49.1 percent of the vote; Brandon Potter, who ousted Rep. Chris Millea of Cranston by attracting 59.9 percent of the vote; Leonela Felix, who won 58.7 percent of the vote while defeating Rep. Ray Johnston of Pawtucket; Brianna Henries, who cruised past Rep. Joe Serodio of East Providence with 61.5 percent of the vote; and Michelle McGaw of Portsmouth, who had the most commanding performance of the primary, winning almost 80 percent of the vote for a seat vacated by Rep. Dennis Canario.

Pawtucket City Councilor Meghan Kallman, a progressive, won the race for a seat vacated by Sen. Donna Nesselbush of Pawtucket.

In other races, former Cranston city councilor Maria Bucci defeated rival Steve Stycos in the Democratic primary for mayor of that city.