A year after he was swept into office with a progressive mandate, Mayor Bill de Blasio and his agenda took a hit on Election Day. Democrats he backed lost key seats upstate and Republicans reclaimed majority control of the State Senate.

De Blasio had tried to help Democrats take control of the Senate by fundraising and lending out staff to struggling campaigns. But he also made himself a target for Republicans who framed his support as interference from the big city’s biggest liberal.

Asked whether the results were a repudiation of him and his agenda, de Blasio said that’s not how he thinks politics works.

“I think it’s about the issues the candidates choose. I think it’s about the vision they put forward. I think it’s about how they reach people at the grassroots.”

He called the Republican surge an “aberration” and warned GOP members to think carefully before they stand in the way of his agenda, which includes increasing the minimum wage, passing the Dream Act and Women’s Equality Act, and campaign finance reform.

“I agree with you that a lot of Republicans are going to try to resist that,” de Blasio told reporters Wednesday. “I think they will do that at their own peril.”