Sen. Scott Brown (R) is taking sides in the race to succeed retiring Rep. Bill Delahunt (D). He endorsed state Rep. Jeff Perry over former state Treasurer Joe Malone in the Republican primary.

Brown announced his endorsement of Perry in a video in which he praises the candidate as “someone who will stand alongside me to bring an independent voice to the commonwealth.”

Perry and Brown, a former state Senator, served together as a small coterie of Republicans in the Legislature for much of the past decade.

Delahunt’s 10th district was one of Brown’s best performing districts in the Senate special election in January.

Another popular GOP figure, former Gov. Bill Weld (R), endorsed Malone on Tuesday. Weld and Malone served side by side in state government in the 1990s.

Two top-tier Democrats are also in the open-seat race — state Sen. Robert O’Leary and District Attorney William Keating.