Invoking the specter of Joe Biden and decrying Democrats whom he says have “clung to the status quo, insisted on using the same old playbook – and isn’t fighting hard enough,” Rep. Seth Moulton launched a primary challenge on Wednesday against Massachusetts Sen.

U.S. Rep. Seth Moulton, a moderate Massachusetts Democrat, said Wednesday that he will challenge U.S. Sen. Edward Markey for the Democratic nomination in next year’s Senate race, arguing it’s time fo...