The above is a map of Massachusetts’s 19th Suffolk House District. As you see, it covers all of the Town of Winthrop and the southeastern one-quarter of the City of Revere.

This is the District that has elected Robert DeLeo since the 1990s. As DeLeo became House Speaker in 2010, the District has had the singular luck to have the most powerful man in our government as its voice — yes, more powerful even than the Governor. That’s because the Speaker controls the movement of all legislation. The Governor may want a bill passed, but if the Speaker isn’t aboard, it won’t even be sent to the floor for a vote.

Let’s look a bit closer at the Speaker’s power, and you’ll see what I am saying. First, the Speaker appoints ALL committee members, even those of the minority party, and perforce he appoints all committee chairs. If you are not on good terms with the Speaker, you’ll get the worst committee assignments — and you’ll be given the worst State House offices.

The Speaker cannot, of course, become too arbitrary in his treatment of his members. They can rebel, and the House has rebelled against Speakers. One legislator, Charles Murphy, rebelled against DeLeo a few years ago; his rebellion gained no backers, and not long after that he resigned his seat.

DeLeo has amassed even greater power than the usual Speaker because since 2015 he has established, and held to, a solid partnership with Governor Baker. Rarely do he and Baker go separate ways on legislation. This partnership has boxed out the Senate President — who in the 1980s and 1990s (William Bulger, Tom Birmingham, Robert Travaglini) was more powerful than the Speakers — who has tended, since Therese Murray took that office, to pursue a more “progressive” stance toward legislation than either Governor or Speaker. That partnership continues today, although the House’s police “reform” bill proceeded without the Governor joining in. On budget matters, DeLeo and Baker have marched as one: no new taxes, prudent allocations of funds.

DeLeo’s leaving office threatens this partnership and, indeed, opens the possibility that the “progressive” State Senate will now call the legislative shots. The police “reform” bill shows it. The bill includes several provisions that undermine policing and also violate the State’s civil service and union contract agreements. The bill might not even have happened had the State Senate not acted first, forcing the House to respond. The House did respond, but with a bill much less invasive than the Senate version. It was styled “emergency’ legislation,. yet after passage in July the two versions sat in committee until last week. (Some emergency !) Governor Baker vetoed the committee compromise bill, and his veto stands because enough House members voted No the first time to assure there will be no veto override.

All that now stands to change. Who will be the new House member from Winthrop and part of Revere ? Who will be House Speaker ?

The first question is of merely local interest. Whoever wins the office will be a rookie. (More about the contest later.) Who will be Speaker matters to everybody. As I see it, there are three potential Speakers : Ronald Mariano of Quincy; Patricia Haddad of Somerset on the South Coast; and the North End’s Aaron Michlewitz, currently the chairman of ways and Means, the committee that works out the annual; State budget.

All three have moderate to conservative voting records; yet it is not clear how much of their moderation arises from loyalty to DeLeo. Yet every Speaker since I can remember, except Salvatore diMasi, has plotted a very conservative course: Tom Finneran, Tom McGee Sr. and John Thompson especially, but even Charles Flaherty, David Bartley and George Keverian, though big builders of State institutions, tried nothing too bold. Their worst failings were budget lassitude : none cared to challenge the demands of public employee unions or construction trades. That hasn’t been the case with Deleo. If anything, he’s a budget hawk. His support for Baker’s sweeping MBTA reforms got them all enacted and sustained. DeLeo also chose to support casino legislation, unlike the two Speakers before him. (Casino legalization seemed destined to be a big deal back in 2012, when it finally was enacted. It hasn’t been that at all. the big dal has been legalization of marijuana sales — also accomplished by the Baker – DeLeo partnership.)

Also credit the Baker – DeLeo partnership with enacting prudent criminal justice reform; a sweeping update of our school funding standards; the end of using Framingham women’s prison as an addiction treatment facility; two major opioid addiction prevention reforms; and full rescue of the Stater’s rainy day fund. Can DeLeo’s successor follow suit ?

We really won’t know until he or she takes office, probably some time in January. Nobody expected Sal diMasi to follow the liberal path, yet he did so. Might Patricia Haddad, a veteran of many terms., now change course ? Unlikely; her District is one of the most conservative-voting Democratic seats in the State. Much the same can be said of Ron Mariano’s Quincy. Even a Speaker can’t move against the sentiments of his or her particular District, and the Districts that elect Mariano and Haddad are in no way hot beds of left-leaning activism. (nor is DeLeo’s Winthrop-Revere. If anything, his District is more conservative than the State as a whole.)

The wild card is Michlewitz. He represents Boston’s North End, Chinatown, Waterfront, part of the South End, and half of loser Roxbury. It’s the same district that elected Sal diMasi. If anything, lefty-leaning sentiment is more widespread in the district than in diMasi’s time just ten years ago. Yet Governor Baker in 2018 carried almost every precinct in Michlewitz’s district, most by big numbers. So there is a case to be made that Michlewitz’s voters want him to follow the kind of prudent yet innovative course that baker exemplifies. If Michlewitz becomes Speaker, I shall certainly call for him to be a Baker — or a slicker, younger DeLeo — rather than a diMasi.

As for the 19th Suffolk District itse4lf, several hopefuls are already calling around for support. There’ll be candidates from Revere and from Winthrop, probably more from Winthrop, as the seat is designed to elect a Winthrop ;person. The Democratic primary will of course be the venue of decision. I have a personal favorite, to whom I committed years ago, but his election is not assured. If there’s five Winthrop candidates and only one from Revere, it could be a close run thing. Thus “clearing the field” will be critical. Can my favored candidate, who has a powerful following, get other ambitious Winthrop guys to give him a clear shot ?

Upon the answer to this kind of question are more offices elected than most of you readers suppose.

— Mike Freedberg / Here and Sphere