Elizabeth Warren has refrained from endorsing a candidate in the presidential race — until now. Sources have told Reuters that the Massachusetts senator plans to endorse presumptive Democratic nominee Hillary Clinton within the next few weeks.Warren was the only remaining female Democratic senator not to endorse Clinton, and in fact, she has actually praised Bernie Sanders. On MSNBC’s Morning Joe , she called him “a real champion of standing up for working families, taking on Wall Street.”However, Warren is motivated to do whatever's necessary to defeat Donald Trump, according to Reuters's sources. Warren is an outspoken critic of Trump and recently tweeted , "Get ready, Donald — we're coming."Clinton's advisors told The New York Times in April that she was considering Warren as a running mate . Reuters's sources said Warren wasn't actively pursing a place on Clinton's ticket but hadn't ruled it out either. If she were the VP candidate, we'd have not only the first female major-party nominee but also the first all-female ticket.