Corporate Boston had better brace for a lot more than overflowing trash and dirty bathrooms if Hub janitors hit the picket lines this fall.

Given past history, the demonstrators are likely to spend more time harassing downtown tower and office building owners than the dopey contractors who actually employ them.

SEIU Local 615, the union for thousands of downtown office cleaners, recently voted to authorize a strike, with the deadline – barring any last-minute extensions – set to run out on Monday.

OK, on paper the target would appear to be their employers, the Maintenance Contractors of New England – a group most people, unless they push brooms for a living, have never heard of.

But in practice, the union may save its most disruptive and colorful tactics for the tower owners who hire the contractors – and by extension the companies, executives and workers who slog to work every morning to offices on State, Federal or Franklin streets.

And if the weather stays as nice as it has been over the past month, well, look out!

Targeting Tower Owners

Fair or not, it’s a game of leverage here. The last time Hub janitors struck, back in 2002, they succeeded in making life miserable for both office tower owners and downtown Boston.

The strategy worked, providing a platform for politicians to grandstand upon, garnering lots of local headlines, and, at the end of the day, producing a contract with some key concessions. At least on paper.

As a reporter at the Boston Herald at the time, I will assure you it was fun to cover. But if you actually worked in one of the downtown towers hit by the strike, it was a headache, plain and simple.

Clad in purple “Justice for Janitors” t-shirts, union members mounted a daily barrage of drum-beating, slogan-chanting parades through downtown Boston, ultimately winding up at the lobby of one or another big tower owner.

Turning up the heat, the union and its supporters also took to blocking key downtown intersections during rush hour, letting Boston’s finest drag them away. The union put pressure on tower owners to take sides and issue statements in support, with those refusing to play ball winding up with demonstrations out front.

International Place developer Don Chiofaro, never one to turn down an opportunity to jump into the spotlight, broke ranks with other tower owners and met with the strikers. Former John Hancock chief David D’Alessandro, then in charge of one of the city’s biggest corporate players, also came out in support.

But Equity Office, one of the largest office building owners in downtown Boston, wouldn’t sit down with the aggrieved workers, arousing the ire of the strikers and their supporters. As a result, the 100 Summer Street tower, where Equity kept its local headquarters, became strike zone central.

Meanwhile, Boston Mayor Thomas Menino and the late Sen. Ted Kennedy jumped into the fray, with Kennedy holding a press conference to praise the strikers and blast one of the main contractors.

It took a month, but the union got its new contract, calling for a boost in pay, and more full-time jobs and health benefits.

Déjà Vu?

Whether the janitors’ union can follow the 2002 blueprint to another victory remains to be seen.

The grievances remain pathetically similar – a dearth of full-time jobs and alleged efforts by the contractor to keep hours down so workers can’t qualify for company health insurance.

But if the janitor’s union follows through on its strike threat, it will be missing some key allies this time around.

Menino is still here, but sadly, Kennedy has long since departed this life, while Cardinal Bernard Law, a big supporter, left for Rome years ago. It is doubtful Sen. Scott Brown would go anywhere near this one, though I’ll reserve judgment on Elizabeth Warren.

The union’s workforce, heavily immigrant and Hispanic, is not likely to be viewed as sympathetically today, either.

But, if anything, the kind of street theater that worked so well back in 2002 for Boston janitors is even more in vogue today, given what we saw with the Occupy encampments last year.

Stay tuned – a demonstration could be coming soon to a street corner or office lobby near you.

Scott Van Voorhis can be reached at sbvanvoorhis@hotmail.com