Elizabeth Warren reacted differently than Bernie Sanders when a crowd in Seattle booed at her mention of the brothers behind the powerful Koch political network that funds much of the conservative and libertarian movement.

The senator for Massachusetts and Democratic 2020 presidential candidate routinely bashes the industrialist billionaires and Republican megadonors during her stump speeches. But on Sunday, the liberal firebrand riffed about Charles and David Koch's work stymieing a bipartisan response to climate change science in the 1990s.

David Koch died last week at the age of 79 after a battle with prostate cancer.

"And then along come big oil, big polluters, the Koch brothers," Warren said to boos from her Seattle town hall audience. "They come in, and they say you know this could be a problem. If our government, our federal government gets really serious about climate change, they’re going to bite into our own profits. If they change the regulations, that’s going to disrupt how we do business. So they have an investment decision to make."

She went on to swipe at the Kochs for investing in politicians rather than green technology, including "experts who deny climate science."

Warren's lack of action after the boos contrasts with the Vermont senator's efforts to shut down a similar response, despite the different context.

A spokeswoman for the Warren campaign did not immediately return the Washington Examiner's request for comment.

Sanders on Saturday scolded the crowd who came to hear him speak at the Minnesota State Fair for cheering David Koch's demise from the disease.

"Yesterday, oligarch David Koch passed away," a questioner began in St. Paul and was met with cheers from the audience.

Sanders replied, "I don’t applaud, you know, the death of somebody. We needn’t do that."