Scott Brown is a dangerous man: dangerous to the world view of Massachusetts Democrats.

The way things are supposed to work around here is we have a Democratic Party primary and then a short while later the swearing-in. During the primary season, a field of cookie-cutter liberals raises money and contends for the backing of unions and progressive groups, especially pro-choice women.

One example would be Martha Coakley campaigning the day before the 2010 special election for US Senate with then-AFL-CIO head Bobby Haynes and Emily’s List director Ellen Malcolm. That usually works, but in this case Coakley was campaigning the day before the general election, not the primary, and Brown was about to clobber her.

He may clobber Elizabeth Warren, too, and with the backing of the very people who built the Massachusetts Democratic Party.

Let’s consider union households, usually about 22 percent to 25 percent of the vote in a general election.  Labor fought alongside Ted Kennedy in countless electoral and legislative battles. Unions provide money and workers for Democrats, and labor leaders are almost uniformly loyal to the party. But last year the unions and legislative Democrats split over collective bargaining rights for municipal worker health care contracts. Recently, the Globe reported that Warren has had difficulty finessing that divide. The labor-Democrat marriage is strained.

And who is there to pick up the pieces? Scott Brown, of course.

According to a recent Suffolk University/7News poll, Brown leads Warren in union households by a 48-41 margin.

The other institutional leg that has historically supported the Democrats was the Catholic Church, which not only no longer has much political clout but also has a few problems of its own. Still, the disrespect the Democrats have shown in piling on the Church has discomfited some Catholics. Scott Brown is ready with pastoral comfort.

How can this be? How can a guy who is a radical and waging a war on women possibly be winning? It isn’t possible in the Democratic world view. Yet women under age 50 are evenly divided between the candidates, according to a recent MassINC Polling Group/WBUR poll.

A year ago, I offered Hugs for Democrats to a party in despair over its chances of even mounting a credible challenger to Senator Brown. Then Warren burst on the scene like a supernova and some Democrats quickly concluded, “no way the professor doesn’t beat this dummy.” Recent polls showing Warren trailing the dummy have again cast some Democrats into a low-grade depression.

And so I offer an absolute gem of a quote about Brown from the progressive Blue Mass Group’s David Kravitz:

He’s still more or less what he’s always been: an affable, somewhat bumbling, mildly conservative fellow who, through a peculiar series of coincidences, wound up way over his head in a job that he’s not very good at. …  It’s hard to get angry at someone you can’t take seriously.

Kravitz quickly acknowledged that he takes Brown seriously as a candidate. Still, could he have been more contemptuous? Perhaps, just perhaps, some of our fellow citizens feel the haughtiness of the state’s elites as well.

I don’t really know how Brown does it but I’ll offer a little theory. He has now been elected as a town selectman, a state representative, a state senator, and, statewide, as a US senator (similar to the electoral path of Paul Cellucci).  If you’re going to be successful as a Republican in this state you can’t do it by just talking to members of your own party. You have to talk to – and more importantly, listen to – everyone. Brown does that. A “listening tour” before you announce isn’t a substitute.

I also think Brown’s years of service in the National Guard serve him well. He must have met all sorts of people in the Guard, including working class voters and Catholics – whether devout, cafeteria, disengaged, or disgusted Catholics. He might have learned that those folks are relatively conservative on social issues and on national security, and he has been able to resonate with them.

The Democrats have the progressives and the professor. But maybe they need to dumb down – like Sen. Scott Brown.

Maurice Cunningham is chairman of the political science department at the University of Massachusetts Boston