Campaigns are living, breathing things. They take on a life of their own, with their own rhythm and momentum, a momentum that can’t be easily thrown off by outside forces. It’s as if they have their own immune systems, which, when working well, recognize alien intrusions and push them aside.

So it was in the Sixth Congressional District, where John Tierney went down to defeat at the hands of Marine veteran Seth Moulton, who cruised past Tierney despite the 18-year incumbent’s effort to invoke a who’s who of Democratic honchos who were in his corner. The dynamics of the race were not working in Tierney’s favor. But trying to resuscitate a flagging campaign by throwing a lot of big-name supporters into the hopper is a move of desperation that rarely delivers.

Tierney had been badly weakened by an illegal gambling ring involving his wife’s brother, for which the congressman’s wife wound up convicted on tax violation charges.

Trying to pump up his reelection effort with endorsements from popular figures like Elizabeth Warren and Joe Kennedy III, as with a harsh attack ad he launched against Moulton late in the race, probably only served to telegraph Tierney’s vulnerability. North Shore voters may love Elizabeth Warren, but you can’t graft that love onto a bedraggled congressional colleague for whom voter affection in the district has been waning. That’s even more true for Nancy Pelosi, who paid a visit to the Bay State in June to help boost Tierney’s struggling reelection fight. It turned out voters in Lynn and Salem didn’t care much what the House Minority Leader from Washington had to say about the intraparty scramble for their congressional seat.

Voters seemed to offer the same indifferent shrug of the shoulders to the double-barreled endorsement of Warren Tolman by Gov. Deval Patrick and Boston Mayor Marty Walsh in the Democratic race for attorney general.

Tolman, a popular former lawmaker and one-time candidate for governor and lieutenant governor, found himself outmatched by Maura Healey, who trounced him nearly 2 to 1. Healey was a political newcomer, but she caught fire as an accomplished prosecutor whose background was a better fit for a job where voters often are more interested in a seasoned professional than someone steeped in the state’s political waters. Meanwhile, Healey’s profile as an openly gay candidate — with a killer outside shot honed during her basketball days at Harvard – gave her some buzz, and a lift with women and gay voters that brought energy and excitement to her side.

Patrick, who expressed his debt to Tolman for his support over the years, seemed to be an almost reluctant booster. He said a lot of people had been twisting his arm to get behind Tolman, and he went out of his way to say Democrats had two excellent choices. There was little equivocation from Walsh, who went all-in with Tolman, whose brother is the state AFL-CIO president and a close labor ally of the mayor’s.

The Globe reported that Walsh’s political operation had more than 700 people out working on behalf of Tolman on Election Day. Joe Rull, a Walsh aide who was a key figure in his mayoral campaign last year, told the Globe there was only so much Walsh could do to affect a statewide race because “at the end of the day, we’re only in control of Boston.”

But it turned out they could not even make that claim, as Healey beat Tolman in Boston by more than 10 points.

Democratic gubernatorial runner-up Steve Grossman banked a boatload of endorsements from elected officials at the start of the race. But he readily acknowledged that the endorsements merely opened the door to conversations where he could make his case to supporters of those officials who were backing him.

It seemed clear that it was Grossman’s own campaign, and the fervor and energy he showed as a candidate in the closing weeks of the race, that helped bring him from far behind in the polls to within 6 points of primary winner Martha Coakley.

As former state transportation secretary Jim Aloisi points out in this new CommonWealth video conversation about yesterday’s primary results, it’s been more than 50 years since publication of The Last Hurrah, the barely fictional ode to James Michael Curley and the days when political machines could deliver votes in bulk to a candidate.

There are plenty of great stories from that era, but democracy seems better off having them as colorful tales of a bygone time.