Sen. Elizabeth Warren is stepping up her attacks against Donald Trump, calling him a "small, insecure money-grubber."
Warren made the remarks during a speech at the Center for Popular Democracy's annual gala in Washington D.C. where she questioned why Donald Trump has not released his tax returns and criticized him for putting his business interests over Americans during the 2006 housing crisis.
"Donald Trump was drooling over the idea of a housing meltdown because it meant that he could buy up more property on the cheap," Warren said. "What kind of a man roots for people to get thrown out of their house?"
Trump quickly struck back on Twitter.
"Goofy Elizabeth Warren, sometimes known as Pocahontas, bought foreclosed housing and made a quick killing. Total hypocrite!" the presumptive GOP presidential nominee wrote.
Trump's tweet alludes to previous reports of Warren flipping properties in the 1990s. A 2012 report by the Boston Herald revealed that the Massachusetts senator bought two homes after the housing crisis and gave her relatives money to purchase other properties.
At the time, Sen. Warren's campaign issued a statement, saying the homes she and her husband bought were to help her family. "They have been able to help relatives buy their homes and her nephew — a contractor — fix up houses," the statement said.
Warren has not endorsed either Hillary Clinton or Bernie Sanders for president, but in recent weeks, she has seemingly embraced her role in portraying Donald Trump as someone she considers an "urgent threat."
Warren's line of attack regarding the housing crisis also echoes a Clinton ad unveiled Tuesday that uses a 2006 audio recording of Trump saying he "sort of hopes [the housing bubble burst] happens."
Some analysts have named Warren as a possible running mate for Hillary Clinton. While Warren is popular icon among progressives, other political watchers have cast doubts on whether Warren is a viable vice presidential candidate, given that the senator has sharply criticized Clinton in the past.
Nevertheless, Warren and Clinton now appear to have a common goal — defeating Donald Trump.