Four Democrats in the state Assembly on Thursday formally endorsed state Senate candidate Zellnor Myrie in his bid oust one of their fellow Democratic colleagues in Albany: Sen. Jesse Hamilton.

The endorsements from Assembly lawmakers Walter Mosley, Diana Richardson, Jo Anne Simon and Robert Carroll are eyebrow-raising: It’s unusual for sitting lawmakers to endorse a primary challenger to an incumbent.

But this is not a typical election year.

Hamilton is one of eight lawmakers who had comprised the Independent Democratic Conference, a faction of senators who had allied with Republicans in the state Senate. The IDC disbanded in April amid mounting political pressure and rejoined the mainline conference fold.

“Our community deserves public servants who lead with transparency, dedication, and a powerful vision for our families,” Richardson said. “I know without a doubt that Zellnor Myrie will be an effective advocate for Central Brooklyn, and I proudly endorse him for State Senate. I will do everything I can to support his candidacy and hope my neighbors will join me in casting their votes for him as well.”