“Forces loyal to Vermont Sen. Bernie Sanders are waging an increasingly public war against Texas Rep. Beto O’Rourke, the new darling of Democratic activists, as the two men weigh whether to seek the party’s presidential nomination in 2020,” NBC News reports.

“The main line of attack against O’Rourke is that he isn’t progressive enough — that he’s been too close to Republicans in Congress, too close to corporate donors and not willing enough to use his star power to help fellow Democrats — and it is being pushed almost exclusively by Sanders supporters online and in print.”

“It’s been the first flashpoint in what promises to be a politically bloody primary — one that has drawn responses from foot soldiers in the Obama and Clinton wings of the party — as Democrats begin to focus on who has the best chance to deny President Trump a second term in the Oval Office.”