Democrat Warren takes step to challenge Trump in 2020

Warren said she had formed an exploratory committee, which will allow her to begin raising money to compete in what is expected to be a crowded Democratic primary field before the November 2020 presidential election.Warren, 69, a senator from Massachusetts since 2013, became one of Trump's fiercest critics during the 2016 presidential race and they have continued to exchange biting insults during his presidency.Trump mockingly refers to her as "Pocahontas" because of her claim to Native American