The Senate delegation from Massachusetts looks set to retain its tag-team of nuclear disarmament advocates into the next presidential term, now that Sen. Edward Markey (D-Mass.) has defeated Rep. Joe Kennedy III (D-Mass.) in a Democratic primary in the blue state.

The Massachusetts Secretary of the Commonwealth at deadline had not released the official results from Tuesday’s primary, but data from The Associated Press, with over 99% of state precincts reporting, showed Markey with more than 55% of the vote, compared to over 44% for Kennedy.

Markey, one of the most liberal members of Congress, reliably partners with other hard-progressive lawmakers to push legislation that would restrict both the use of nuclear weapons, and the configuration of nuclear forces. 

In this session of Congress, he has filed bills that would make the nuclear arms limits of the New START treaty the law of the land, require the U.S. to declare that it would not be the first nation to fire nuclear weapons in a fight, and prohibit even preparations for future nuclear-explosive testing. None of the bills have much chance for advancement out of committee, let alone passage, in the GOP-controlled Senate.

Markey’s colleague, Sen. Elizabeth Warren (D-Mass.), has also advocated for a no first-use policy: something war scholars and strategists dismiss as an unverifiable promise destined to be disregarded in wartime, but which proponents say can diffuse global tension among nuclear-armed adversaries if paired publicly with a corresponding change in force structure.

Markey is now heavily favored to win a second term in the Senate in the Nov. 3 election, in which he’ll face Republican challenger Kevin O’Connor, a lawyer.

In beating Kennedy — who now will be leave the House in January after four terms, with the dubious distinction of being the first member of his politically distinguished family to lose a race for Congress in Massachusetts — Markey became a rallying point for the leftmost wing of the Democratic Party. One commentator likened Markey to “the second coming of [Sen.] Bernie Sanders [I-Vt.],” who did not endorse anybody in the primary contest just ended.