After their first meeting this week, the State House’s new Big Three — Governor Charlie Baker, Senate President Stan Rosenberg, and House Speaker Bob DeLeo — all talked of cooperation and collegiality. But what are the real power dynamics on Beacon Hill? Here’s a back-of-the-napkin explanation.

Heather Hopp-Bruce/Globe staff
After their first meeting this week, the State House’s new Big Three — Governor Charlie Baker, Senate President Stan Rosenberg, and House Speaker Bob DeLeo — all talked of cooperation and collegiality. But what are the real power dynamics on Beacon Hill? Here’s an explanation.
Governor Charlie Baker: Wants to establish a bipartisan tone early on, and opiate addiction is an issue where getting to “yes” shouldn’t be hard. Bonus: It’s a cause dear to Steven Tolman, AFL-CIO president. Baker’s broader agenda will likely conflict with organized labor, but on this one, Tolman should be an ally.
Big issue: opioids. And here, Attorney General Maura Healey, a charismatic new Dem star — and possibly a future gubernatorial candidate — also wants to hit the ground running. How do we know? She jumped into the game on opioids. A clear sign she wants to be a starting player.
Speaker of the House Robert DeLeo: By State House standards, a pretty regular guy. Neither a huge ego nor a credit hog. Has incentives to play ball with Baker. Bruised by the prosecutors’ allegations in the Probation Department trial, wants to be seen as part of constructive governance. Also wants Baker to reconsider that legislative pay hike . . .
Big issue: Leadership pay.
Senate President Stan Rosenberg: New to power in the Senate. Had a tough December; skittish senators are wondering about his leadership skills. Liberals hope he’ll carry their agenda, but as the shakiest member of the Big Three, he has to prove that the State House agenda won’t be driven by a Baker-DeLeo axis.
Big issue: Avoid being the odd man out, like former House Speaker Charlie Flaherty was in the early 1990s and former Senate President Tom Birmingham in the mid-’90s.