Several senior staffers who worked for Sen. John Fetterman, D-Penn., have resigned in order to take positions with left-wing groups as the senator has become more moderate on certain issues. 

Fetterman's deputy communications director Nick Gavio, communications director Joe Calvello and press aide Emma Mustion all resigned this month, according to The Washington Times.

The Pennsylvania senator has taken more moderate stances on certain issues than most of his fellow Democratic senators, including tougher border security policies and supporting Israel during its ongoing war against Hamas. 

According to the Times, Calvello accepted a job at Chicago Mayor Brandon Johnson's office, calling him a "true progressive."

Meanwhile, Gavio accepted a position with the left-wing Working Families Party.

Fetterman has indicated in the past that he doesn't consider himself a "progressive."

“I just think I’m a Democrat that is very committed to choice and other things. But with Israel, I’m going to be on the right side of that,” he said during a previous interview with NBC News.