Healey’s ascension coincides with the dispiriting collapse of politics in Mass.

Maura Healey. Photo (cc) 2015 by Charlie Baker. Yes, that’s what the photo credit says. Yes, I realize that’s Baker on the left-hand side of the frame.

State Sen. Sonia Chang-Díaz’s withdrawal from the gubernatorial race on Thursday underscores the astonishing collapse of politics in Massachusetts. This is a state where politics has traditionally been a year-round sport. In the past, an open governor’s seat would have attracted multiple candidates. Instead, Attorney General Maura Healey will run uncontested for the Democratic nomination and will probably beat either of the two Republicans who are running.

The Axios Boston headline this morning puts it this way: “AG Healey on track to be Massachusetts’ first elected female governor.” In June. Nearly five months before Election Day.

Contrast what’s happening today with 1990, when Gov. Michael Dukakis retired. Three prominent Democrats sought the nomination — Boston University president John Silber, Attorney General Frank Bellotti and Lieutenant Gov. Evelyn Murphy. Although Murphy ended up withdrawing, Silber beat Bellotti in a closely fought race. Silber, in turn, was defeated by former federal prosecutor Bill Weld, who won the Republican nomination by beating House Republican leader Steve Pierce.

More recently, in 2006, a relatively unknown former Justice Department official, Deval Patrick, won the Democratic primary for governor with less than 50% of the vote against businessman Chris Gabrieli and Attorney General Tom Reilly. That November, Patrick defeated Lt. Gov. Kerry Healey and several independent candidates, the most prominent of whom was the late businessman Christy Mihos.

So how did Healey end up running unopposed for the Democratic nomination? There are some unique factors at play. Republican Gov. Charlie Baker took his time in announcing he wouldn’t seek another term, which gave a significant advantage to the well-known, well-funded Healey. Former Boston Mayor Marty Walsh decided he’d rather stay in Washington than run for governor.

I worry, though, that we’re all losing interest in politics. Healey is first-rate, smart, personable and progressive. After her, though, who? U.S. Rep. Ayanna Pressley? Boston Mayor Michelle Wu? Maybe. Both are at a relatively early stage of their political careers — especially Wu — so perhaps we just have to give it time.

As for the Republicans, who have produced a slew of governors over the years to act as a moderating force against the dominant Democrats, the situation is sad indeed. Two Republicans are running for governor this year. One, state Rep. Geoff Diehl, is a full-blown Trumper. The other, businessman Chris Doughty, is trying to position himself as a Baker-style moderate — but he opposes abortion rights and has taken stands that suggest he supporters deeper tax cuts than Baker would support.

For those of us who’ve been following Massachusetts politics for years, it’s a dispiriting time. I hope it’s just temporary.