The ninth Democratic debate takes place Thursday night in the Brooklyn Navy Yard, in New York City.

While former secretary of state Hillary Clinton and U.S. Senator from Vermont Bernie Sanders are expected to duke it out in an intensifying battle for the party nomination, themes of the weak economy and the struggles of the middle class are likely to take center stage. And you can bet that small businesses will be singled out for their role as the most important job creators in the U.S.

Certainly the Brooklyn Navy Yard is a great place to make this hat tip. Over the past few years it has transformed itself from urban industrial graveyard into a vibrant entrepreneurial hub.

While all things Brooklyn are hipster-hyped today, the resurgence has been a long time coming. During World War II, employment at the Brooklyn Navy Yard peaked at 70,000 workers, who turned out all kinds of vessels, including battleships. (The Missouri was made in Brooklyn.) The yard fell into disrepair in the 1960s, along with the city itself, and by the 1980s, a scant 100 people were working there, according to The New York Times. Today about 300 businesses employ 7,000 people at the BNY.

Some of New York's top-shelf names now operate there, including TV and movie production outfit Steiner Studios, the Brooklyn Roasting Co., and Gilt Groupe, the former unicorn, valued at more than $1 billion, purchased by Saks Fifth Avenue parent Hudson's Bay Co. in 2016. Mast Brothers, the chocolatier, has just opened up a 65,000-square-foot manufacturing facility there, and one of New York's beloved delicatessens, the 100-year-old Russ & Daughters, plans to open a facility of equal size to fulfill orders from around the nation.

Maybe some of the entrepreneurial spirit will rub off on the candidates. Both have struggled to portray themselves as advocates of struggling workers and entrepreneurs. Clinton has labeled herself the small-business presidential candidate, although she has laid out only vague ideas about how to bolster investment in entrepreneurship. More recently, she released a proposal to encourage profit sharing by private companies. For his part, Sanders has staked his campaign on attacking corporate greed and Wall Street.

In recent days, Sanders has stumped with striking Verizon workers, railing about large corporations destroying the middle class through cost-cutting and low wages that create economic stagnation and widen the gulf between the 1 percenters and everyone else.

Here's what Sanders said in a tweet yesterday:

That basic message, about the obligation business owners have toward their employees, is something that entrepreneurs consider on a daily basis as they build out their companies in places like the Brooklyn Navy Yards. And it's more than lip service.